Nowadays it's hard to imagine scientific activity a person without a microscope. The microscope is widely used in most laboratories of medicine and biology, geology and materials science. The results obtained using a microscope are necessary when making an accurate diagnosis and monitoring the progress of treatment. Using a microscope, new drugs are developed and introduced, and scientific discoveries are made.
Microscope - (from the Greek mikros - small and skopeo - look), an optical device for obtaining an enlarged image of small objects and their details that are not visible to the naked eye. The human eye is capable of distinguishing details of an object that are separated from each other by at least 0.08 mm. Using a light microscope, you can see parts with a distance of up to 0.2 microns. An electron microscope allows you to obtain a resolution of up to 0.1-0.01 nm. The invention of the microscope, a device so important for all science, was primarily due to the influence of the development of optics. Some optical properties of curved surfaces were known to Euclid (300 BC) and Ptolemy (AD), but their magnifying ability was not found practical application. In this regard, the first glasses were invented by Salvinio degli Arleati in Italy only in 1285. In the 16th century, Leonardo da Vinci and Maurolico showed that small objects are best studied with a magnifying glass.
The first microscope was created only in 1595 by Zacharius Jansen (Z. Jansen). The invention involved Zacharius Jansen mounting two convex lenses inside a single tube, thereby laying the foundation for the creation of complex microscopes. Focusing on the object under study was achieved through a retractable tube. The microscope magnification ranged from 3 to 10 times. And it was a real breakthrough in the field of microscopy! He significantly improved each of his next microscopes.
During this period (XVI century), Danish, English and Italian research instruments gradually began their development, laying the foundation of modern microscopy. The rapid spread and improvement of microscopes began after Galileo (G. Galilei), improving the telescope he designed, began to use it as a kind of microscope (), changing the distance between the lens and the eyepiece.
Galileo's microscope year.
In 1625, a member of the Roman “Academy of the Vigilant” (“Akudemia dei lincei”) I. Faber proposed the term “microscope”. The first successes associated with the use of the microscope in scientific biological research were achieved by R. Hooke, who was the first to describe a plant cell (around 1665). In his book Micrographia, Hooke described the structure of a microscope.
In 1681, the Royal Society of London discussed this peculiar situation in detail at its meeting. The Dutchman A. van Leenwenhoek described amazing miracles that he discovered with his microscope in a drop of water, in an infusion of pepper, in the mud of a river, in the hollow of his own tooth. Leeuwenhoek, using a microscope, discovered and sketched spermatozoa of various protozoa and details of the structure of bone tissue ().
The best Leeuwenhoek magnifying glasses were magnified 270 times. With them, he saw for the first time blood cells, the movement of blood in the capillary vessels of the tadpole's tail, and the striping of muscles. He discovered ciliates. He plunged for the first time into the world of microscopic single-celled algae, where the border between animal and plant lies; where a moving animal, like a green plant, has chlorophyll and feeds by absorbing light; where the plant, still attached to the substrate, has lost chlorophyll and ingests bacteria. Finally, he even saw bacteria in great variety. But, of course, at that time there was still no remote possibility of understanding either the significance of bacteria for humans, or the meaning of the green substance - chlorophyll, or the boundary between plant and animal.
In 1668, E. Diviney, by attaching a field lens to the eyepiece, created an eyepiece modern type. In 1673, Havelius introduced a micrometer screw, and Hertel proposed placing a mirror under the microscope table. Thus, the microscope began to be mounted from those basic parts that are part of a modern biological microscope.
In 1824, the enormous success of the microscope was achieved by Sallig's simple practical idea, reproduced by the French company Chevalier. The lens, which previously consisted of a single lens, was divided into parts; it began to be made from many achromatic lenses. Thus, the number of parameters was multiplied, the possibility of correcting system errors was given, and for the first time it became possible to talk about real large magnifications - 500 and even 1000 times. The limit of ultimate vision has moved from two to one micron. Leeuwenhoek's microscope was left far behind. In the 70s of the 19th century, the victorious march of microscopy moved forward. The speaker was E. Abbe.
The following was achieved: First, the maximum resolution moved from half a micron to one tenth of a micron. Secondly, in the construction of the microscope, instead of crude empiricism, a high level of science was introduced. Thirdly, finally, the limits of what is possible with a microscope are shown, and these limits are conquered.
The main parts of a light microscope (Fig. 1) are the lens and the eyepiece, enclosed in a cylindrical body - a tube. Most models intended for biological research are equipped with three lenses with different focal lengths and a rotating mechanism designed for quick change - a turret, often called a turret. The tube is located on the top of a massive tripod, which includes a tube holder. Just below the lens (or a turret with several lenses) there is a stage on which slides with the samples under study are mounted. Sharpness is adjusted using the coarse and fine tuning, which allows you to change the position of the stage relative to the lens.
Optical microscopes Near-field optical microscope Confocal microscope Two-photon laser microscope Electron microscopes Transmission electron microscope Scanning electron microscope Scanning probe microscope Scanning atomic force microscope Scanning tunneling microscope X-ray microscopes Reflection X-ray microscopes Projection X-ray microscopes Laser X-ray microscope (XFEL) Differential interference contrast microscopes
In the modern world of digital technology, optical microscopes are considered obsolete; they have been replaced by digital analogues. This provides both advantages and disadvantages. But, undoubtedly, digital microscopes have greater potential and capabilities, which any student can now use.
A microscope is a laboratory optical system for obtaining magnified images of small objects for the purpose of viewing, studying and applying in practice. The combination of manufacturing technologies and practical use of microscopes is called microscopy.
Using microscopes, the shape, size, structure and many other characteristics of micro-objects, as well as the microstructure of macro-objects, are determined.
The history of the creation of the microscope as a whole took a lot of time. Gradually more developed optical technologies led to the emergence of better lenses, more precise holding devices.
By the end of the 20th century, optical microscopes had reached the pinnacle of their development. The next stage was the advent of digital microscopes, in which the lens was replaced by a digital camera.
Actually, the main difference between a digital microscope and a conventional one is the absence of an eyepiece through which the object is observed by the human eye. Instead, a digital camera is installed, Firstly, which does not produce distortion (the number of lenses is reduced), Secondly, color rendition improves, and images are obtained in digital form, which allows for additional post-processing, as well as storing huge amounts of photos on just one hard drive.
The Digital Blue QX5 digital microscope is designed for use in school environments. It is equipped with a visual-to-digital information converter, which ensures real-time transmission of images of a micro-object and micro-process to a computer, as well as their storage, including in the form of digital video recording. The microscope has a simple structure, a USB interface, and two-level illumination. It came with software with simple and clear interface.
With modest, from a modern point of view, system requirements it allows:
Increase and studied objects placed on the stage, 10, 60 and 200 times (the transition is carried out by turning the blue drum)
Use both transparent and opaque objects, both fixed and unfixed
Research surfaces of fairly large objects that do not fit directly on the stage
Photograph, and also take video of what is happening by pressing the corresponding button inside the program interface
Record what is observed, without worrying about its safety at this moment - the files automatically end up on the computer’s hard drive.
Set shooting parameters, changing the frame rate - from 4 frames per second to 1 per hour
Produce the simplest changes in the resulting photographs without leaving the microscope program: apply signatures and indexes, copy parts of the image, and so on.
Export results for use in other programs:
graphic files are in *.jpg or *.bmp formats, and video files are in *.avi format
Collect demonstration collections—“strip films”—from the results of photo and video shooting.(the program memory can simultaneously store 4 sequences, including up to 50 objects each). Subsequently, a selection of frames that are temporarily unused can be safely disassembled, since the graphic files remain on the computer’s hard drive
Print received graphic file in three different modes:
9 reduced images on an A4 sheet, a whole A4 sheet, an enlarged image divided into 4 A4 sheets
Demonstrate objects under study and all actions performed with them on the monitor personal computer and/or on the projection screen if a multimedia projector is connected to the computer
What does a digital microscope give to teachers and students in relation to biology lessons?
One of the biggest challenges for a biology teacher when conducting laboratory work with a traditional microscope is the virtually impossible ability to understand what his students are actually seeing. How many times do the guys call for something completely wrong - in sight is either the edge of the drug, or an air bubble, or a crack... It’s good if there is a permanent laboratory assistant or trained public assistants to carry out such work required by the program. And if you are alone - for 25 people and 15 microscopes? And the microscope standing in the middle of the desk (one for two!) cannot be moved - otherwise all the light and sharpness settings will be lost, and the results of the work (as well as time and interest) will be lost.
The same classes are much easier and more effective if laboratory work is preceded by an introductory briefing conducted using a digital microscope.
In this case, the actual actions performed and simultaneously demonstrated through the projector with the drug and the resulting image are best helpers. They clearly present to the student the correct course of action and the expected result. Image sharpness and computer version microscope is achieved by turning the screws. It is also important that you can indicate and sign parts of the drug by putting together a slide show from these frames. This can be done both immediately during the lesson and in the process of preparing for it.
After such introductory instruction, carrying out laboratory work using traditional optical microscopes becomes easier and more efficient. If you do not have magnifying glasses, then this microscope can be used as a binocular (10x or 60x magnification). The objects of study are flower parts, leaf surfaces, root hairs, seeds or seedlings. And mold - even mucor or penicillium? For arthropods, these are all their interesting parts: legs, antennae, mouthparts, eyes, integument (for example, butterfly wing scales). For chordates - fish scales, bird feathers, wool, teeth, hair, nails, and much, much more. This is not a complete list.
It is also important that many of these objects, after research organized using a digital microscope, will remain alive: insects - adults or their larvae, spiders, mollusks, worms can be observed by placing them in special Petri dishes (there are two of them in the set with each microscope + tweezers, pipette, 2 jars with lids for collecting material). And any indoor plant, brought in a pot at a distance of about 2 meters to the computer, easily becomes an object of observation and research, without losing a single leaf or flower. This is possible due to the fact that the top part of the microscope is removable, and when brought to an object it works like a webcam, giving 10x magnification. The only inconvenience is that focusing is done only by tilting and zooming in and out. But, having caught the desired angle, you can easily take a photograph without reaching for the computer - right on the part of the microscope in your hands, there is the necessary button: press once - you get a photo, press and hold - a video is taken. The quality of graphic files obtained using a digital microscope.
Leaf epidermis
The leaf epidermis is the integumentary tissue of the leaf, otherwise it is called the skin. It is formed by one layer of flat cells that fit tightly to each other. Under a microscope, these cells appear light and transparent due to the fact that a significant volume in them is occupied by a central vacuole filled with cell sap. The vacuole pushes the nucleus and all cellular organelles to the cell periphery. However, the nucleus is clearly visible in every cell; all hereditary information is stored in it. Chloroplasts are usually absent in the main cells of the leaf epidermis. Among the main cells of the skin, cells of a different shape stand out; they lie in pairs, forming stomata. Each stoma consists of two bean-shaped guard cells, and between these cells there is a lens-shaped gap. This gap is called the stomatal gap and represents the intercellular space. The shape of the stomatal fissure and its size can vary depending on how closely the guard stomatal cells adhere to each other. In the guard stomatal cells you can see the nucleus, and they always contain chloroplasts that carry out the process of photosynthesis. On the outer surface, each cell of the leaf skin is covered with a special protective layer - the cuticle. The cuticle may be thick and tough. It may contain fat-like substances and wax. The cuticle must be transparent so as not to impede the penetration of sunlight to the internal tissues of the leaf, where the process of photosynthesis is actively taking place. The epidermis plays a very important role in the life of leaves. It protects the sheet from damage and drying out. Air enters the leaf through open stomatal slits; it is necessary for respiration and photosynthesis. Also, oxygen, which is formed during photosynthesis, and water vapor are released through open stomatal slits. If the plant lacks water, for example in hot, dry weather, the stomatal fissures close. This is how the plant protects itself from excessive water loss. At night, the stomata are also usually closed.
Seed embryo
The embryo is the most important part of the seed. In fact, it is a microscopic plant that has all the organs: an embryonic shoot with an embryonic stem, embryonic leaves and an embryonic apical bud, as well as an embryonic root. In the preparation, the embryonic shoot is directed in one direction, the embryonic root is oriented exactly in the opposite direction. In the area between the embryonic bud, covered by the embryonic leaves, and the root there is an embryonic stem. Directly adjacent to the embryo on one side is the cotyledon. Its cells are the same in staining intensity as the cells of the stem. The cotyledon is a special leaf of the embryo. The cotyledons protect the embryonic bud and are the first to appear on the soil surface. One cotyledon is visible on the preparation, therefore, this embryo belongs to monocotyledonous plants. It is better to view the seed embryo under a low magnification of the microscope so that it can fit entirely into the field of view of the microscope.
Onion scale skin
The bulb is a modified shoot with a short flat stem (bottom) and fleshy, succulent leaves and scales. Therefore, onion skin is the epidermis of the leaf, which develops in the dark without access to light, resulting in the absence of chloroplasts in the cells of the onion skin. Instead of chloroplasts, these cells contain colorless plastids - leucoplasts. Onion skin cells have an elongated shape, close to rectangular. The cell boundaries are clearly visible; they are represented by transparent membranes, hard enough to maintain the shape of the cells. Through cell membranes it is possible to transfer water from cell to cell, as well as substances dissolved in water. The cells appear light transparent due to the fact that a significant volume of them is occupied by a large central vacuole with cell sap. The vacuole is where water is stored in the cell. It may contain in dissolved form reserve nutrients, pigments, solutions of organic acids, mineral salts and various waste products of the plant cell. The vacuole pushes the nucleus and cytoplasm to the periphery of the cell, while the cytoplasm is divided into separate strands. Strands of cytoplasm are revealed under a microscope when high magnification in the form of narrow ribbons extending as rays from the core. The strands of the cytoplasm exhibit a granular structure, which is associated with the presence of various organelles in the cytoplasm.
Root cap
The apex of the root is elongated into a cone and directed towards the center of the Earth. It is protected by the root cap, which is a cap at the top of the root. It consists of several layers of cells. These cells play a very important role in deepening the root into the soil. Cells peel off from the surface of the cap, and mucus is released, which lubricates the soil and ensures the root slides deeper. There is a constant replenishment of cells from the inner surface of the root cap. With its inner surface, the root cap is adjacent to the very apical part of the root, where cell division constantly occurs, that is, the educational tissue is located. Due to the educational tissue of the root apex, the cells of the root cap are constantly replenished. In the preparation, the root cap zone is clearly distinguished from the root apex. The root cap in the form of a crown frames the educational zone of the root. The cells in it lie more loosely than at the top of the root. The outer edge is uneven due to the listening cells. The thickness of the root cap layer in the most voluminous place is several tens of cells.
Pollen from a flowering plant
Pollen is produced inside the anther of the stamen of a flowering plant. Ripe pollen takes part in the pollination process, that is, it is transferred from the stamens to the stigma. If pollination does not occur, no fruit will form. Pollen is carried by wind or insects, depending on the type of pollination the flower is adapted to. Pollen can be transferred to the stigma of the same flower where it ripened (self-pollination), to the stigmas of other flowers of the same plant, as well as to the stigmas of flowers of other plants of the same species (cross-pollination). When analyzed under a microscope, pollen is revealed in the form of grains with a pronounced morphology. The surface of a dust grain is covered with a complex protective shell, on which protrusions or tubercles of various shapes can be detected. These structures are a morphological species characteristic of the plant. Beneath the shells of pollen grains are living cells. One cell is called vegetative. When a pollen grain germinates on the stigma of the pistil, it forms a pollen tube. The pollen tube passes through a hole in the shell of the pollen grain and grows, moving inside the stigma and style of the pistil, towards the ovary. In addition to the vegetative cell, the germinating pollen grain contains male reproductive cells - sperm, there are two of them. It is they who participate in the fertilization process, moving along the pollen tube to the ovary.
Tree branch cut
Tree branching is the process of formation of new shoots. An increase in the number of shoots leads to an increase in the surface of the leaves, which ensure the process of photosynthesis, through which the plant produces all the organic substances it needs. The long axis of each shoot is the stem. The cross section clearly shows that the outside of the stem is covered with a skin that protects the stem from environmental influences. Adjacent to the inside of the skin is a cork - a multi-layered tissue in which there are no living cells. On a section, thick cell membranes are visible in the composition of the cork; they are impermeable to water and air. In some places of the plug there are areas where the cells do not fit tightly to each other, but are located loosely. These are lentils, structures through the intercellular spaces of which gas exchange occurs. Under the stem plug is the bark. It is formed by different tissues. Along the very edge of the food lie living cells with thickened membranes and starch grains. The inner part of the cortex is called the bast, which includes conductive tissue, parenchyma cells and bast fibers. The main conducting element of the bast is sieve tubes with companion cells. Sieve tubes are formed by long living cells located strictly above each other. At the junction of these long cells there are many small holes, the combination of which resembles a sieve, which explains the name of these cells. The sieve tubes are collected in bundles, between which there are parenchyma cells and bast fibers. Sieve tubes conduct substances synthesized in the leaves to lower parts of the plant. To the center of the bast there is wood. This is another conductive tissue; it conducts water and mineral and organic substances dissolved in it from underground organs to aboveground ones. The conductive function in wood is performed by vessels and tracheids. The vessels consist of dead cells, the membranes of which are thickened and lignified. There are no partitions between the cells, and, in fact, the vessel is a tube with numerous pores in the wall. Tracheids also consist of dead cells, but with partitions. The tracheid cells are highly elongated and have pointed ends, which form oblique septa. The walls of the tracheids are also lignified; there are many pores in them and in the partitions. The core is located towards the center of the wood. It is formed by living parenchyma cells, similar to the parenchyma cells of the cortex. These cells perform a storage function. Between the bast and the wood lies a thin layer of cells capable of division - this is the cambium. Thanks to the division of cambium cells, the stem grows in thickness. A larger number of cambium cells turn into wood, a smaller number into bast. The growth of wood per year based on the thickness of the stem is called an annual ring. By the number of growth rings, you can calculate the age of the cut branch.
Cutting the stem of a herbaceous plant
Herbaceous plants lack erect above-ground stems that can survive winters. Their stems are soft, juicy, lignification, if observed, is weak. The bulk of the stem is represented by parenchyma; the cambium is absent in the vascular bundles or its activity is weakly expressed. This preparation shows a cross section of a monocotyledonous herbaceous plant. The outside of the stem is covered with cuticle. It's thin protective film of fat-like substances that covers the epidermis, formed by cells lying in one layer. Beneath the epidermis is a thin layer of cells that may contain chloroplasts. Deeper than this layer is the main tissue of the stem - parenchyma, in which there is no division into bark and pith. In the parenchyma there are vascular bundles, which include sieve tubes with companion cells and 2 - 3 large vessels. Along the periphery of the stem the bunches are smaller, closer to the center of the stem they are much larger. Water rises through the vessels from the soil with mineral and organic substances dissolved in it. Through sieve tubes, substances synthesized in the leaves flow out to lower parts of the plant.
Cross section of the root
A root is a vegetative organ of a plant that is located in the soil. The root performs very important functions. It anchors the plant in the soil, absorbs water with mineral and organic substances dissolved in it, some substances synthesized in the leaves of the plant are deposited in the root cells as reserves. Along its length, the root is divided into several zones, each of which performs its own specific functions. This preparation shows a section of the root through the absorption zone. This is the root hair zone. Root hairs are outgrowths of root integumentary tissue cells. They can reach 1 cm in length. These structures increase the absorptive surface of the root. The integumentary tissues of the root include 1 - 2 rows of cells covering the outside of the root. These cells fit tightly together and secrete mucus. Beneath them, deep in the root, is the bark. The membranes of the outer layers of the cortex cells are suberized and perform protective and supporting functions. Under this protective layer of cells is the parenchyma, which is represented by living cells with thin walls. Spare nutrients are deposited in these cells. The bark surrounds the central cylinder of the root. At the border of the central cylinder lies a layer of cells capable of division, due to which lateral and adventitious roots can form. The main part of the central cylinder is occupied by conducting tissues: vessels and sieve tubes. Strands of these tissues stretch along the entire root and pass, without interruption, to other organs. Through vessels, water with dissolved mineral salts flows to the above-ground organs. Through sieve tubes, solutions of organic substances formed in the leaves during photosynthesis enter the root parenchyma.
In the context of the transition of general education to specialized education of students at the senior level of school, improving the quality of biological education and the level of biological knowledge of students and graduates of secondary schools can be achieved by introducing the use of a digital microscope into school practice.
A digital microscope can be used to conduct laboratory work in advanced-level elective courses in which they study in depth separate sections basic biology course. Such work goes beyond basic education and includes practical and laboratory work, which, using a digital microscope, will allow students to feel like researchers when studying tissues of plants, animals, and humans.
Using a digital microscope together with a computer in a biology lesson allows you to get an enlarged image of the object being studied (micropreparation) on the monitor screen (when working in a group or in classes with a small number of students) or on a large screen (when working with a whole class) using an external projection device connected to a computer.
A digital microscope allows
· study the object under study not by one student, but by a group of students at the same time;
· use images of objects as demonstration tables to explain a topic or when questioning students;
· use multi-level tasks for students of the same class;
· create presentation videos on the topic being studied;
· use images of objects on paper as handouts or reporting material.
The use of a digital microscope when conducting school biological research gives a tangible didactic effect in terms of motivation, systematization and deepening of students’ knowledge, that is, the formation of so-called learning opportunities, the development of students’ abilities to acquire and assimilate knowledge.
In conditions of distance learning for children, a digital microscope allows you to:
Transform the most ordinary surrounding objects into objects of research;
Form unusual images of various objects on a computer screen;
Create presentations with special effects and music;
View the image on a monitor screen or use a multimedia projector to transfer it to a large screen;
Make video recordings;
Compile collections of various images and videos;
Carry out your own research without leaving home;
Feel the significance of yourself and your activities;
Self-realization.
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Network biology teacher Maslova O. V. DIGITAL MICROSCOPE AND ITS APPLICATION IN STUDYING BIOLOGY
In the modern world of digital technology, optical microscopes are considered obsolete; they have been replaced by digital analogues. This provides both advantages and disadvantages. But, undoubtedly, digital microscopes have greater potential and capabilities, which any student can now use. A microscope is a laboratory optical system for obtaining magnified images of small objects for the purpose of viewing, studying and applying in practice. The combination of manufacturing technologies and practical use of microscopes is called microscopy. Using microscopes, the shape, size, structure and many other characteristics of micro-objects, as well as the microstructure of macro-objects, are determined. Actually, the main difference between a digital microscope and a conventional one is the absence of an eyepiece through which the object is observed by the human eye. Instead, a digital camera is installed, firstly, it does not produce distortions (the number of lenses is reduced), and secondly, color rendition is improved, and the images are obtained in digital form, which allows for additional post-processing, as well as storing huge amounts of photographs on just one hard drive.
Digital microscope Digital Blue QX5 The digital microscope is equipped with a visual-to-digital information converter, which ensures real-time transmission of images of a micro-object and micro-process to a computer, as well as their storage, including in the form of digital video recording. The microscope has a simple structure, a USB interface, and two-level illumination. It came with software with a simple and intuitive interface. With modest, from a modern point of view, system requirements, it allows you to: Enlarge the studied objects placed on the stage by 10, 60 and 200 times (the transition is carried out by turning the blue drum) Use both transparent and opaque objects, both fixed and unfixed Examine the surfaces of fairly large objects that do not fit directly on the stage Take photographs, as well as make video recordings of what is happening by pressing the appropriate button inside the program interface Record what is observed without worrying at this moment about its safety - the files automatically end up on the computer’s hard drive. Set shooting parameters by changing the frame rate - from 4 frames per second to 1 per hour. Make simple changes in the resulting photographs without leaving the microscope program: apply signatures and indexes, copy parts of the image, and so on.
Digital microscope Digital Blue QX5 The digital microscope also allows you to: Export results for use in other programs: graphic files - in *. jpg or *. bmp, and video files are in *. avi Collect demonstration collections - “strip films” - from the results of photo and video shooting (the program’s memory can simultaneously store 4 sequences, including up to 50 objects each). Subsequently, a selection of frames that are temporarily unused can be safely disassembled, since the graphic files remain on the computer’s hard drive. Print the resulting graphic file in three different modes: 9 reduced images on an A4 sheet, an entire A4 sheet, an enlarged image, divided into 4 A4 sheets. Display the research items. objects and all actions performed with them on a personal computer monitor and/or on a projection screen if a multimedia projector is connected to the computer.
What does a digital microscope give to teachers and students in relation to biology lessons? If you do not have magnifying glasses, then this microscope can be used as a binocular (10x or 60x magnification). The objects of study are flower parts, leaf surfaces, root hairs, seeds or seedlings. And mold - even mucor or penicillium? For arthropods, these are all their interesting parts: legs, antennae, mouthparts, eyes, integument (for example, butterfly wing scales). For chordates - fish scales, bird feathers, wool, teeth, hair, nails, and much, much more. This is not a complete list.
Laboratory equipment for carrying out observations using a digital microscope It is also important that many of these objects, after research organized using a digital microscope, will remain alive: insects - adults or their larvae, spiders, mollusks, worms can be observed by placing them in special cups Petri (there are two of them in the set with each microscope + tweezers, a pipette, 2 jars with lids for collecting material). And any indoor plant, brought in a pot at a distance of about 2 meters to the computer, easily becomes an object of observation and research, without losing a single leaf or flower. This is possible due to the fact that the top part of the microscope is removable, and when brought to an object it works like a webcam, giving 10x magnification. The only inconvenience is that focusing is done only by tilting and zooming in and out. But, having caught the desired angle, you can easily take a photograph without reaching for the computer - right on the part of the microscope in your hands, there is the necessary button: press once - you get a photo, press and hold - a video is taken.
Spruce needles viewed under a digital microscope
Additional features of a digital microscope You can add a digital microscope to the Archimedes digital laboratory. This will significantly expand its capabilities.
In conditions of distance learning for children, a digital microscope allows you to turn the most ordinary surrounding objects into objects of research; create unusual images of various objects on the computer screen; create presentations with special effects and music; view the image on a monitor screen or use a multimedia projector to transfer it to a large screen; make video recordings; compile collections of various images and videos. o carry out your own research without leaving home; n to feel the significance of yourself and your activities; self-realization
We wish you good luck and success!
The appearance of a digital microscope in school not only allows students to see something new, but first of all helps the teacher to competently organize classroom and extracurricular activities. The use of a digital microscope in biology lessons allows you to increase interest in the subject, improve the quality of learning, reflect the essential aspects of biological objects, embodying life is the principle of clarity, to bring to the fore the most important (from the point of view of educational goals and objectives) characteristics of the objects and natural phenomena being studied.
The material obtained using a digital microscope can be used both in the educational process and in extracurricular activities (club, elective course, elective course).
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Using the capabilities of a digital laboratory in teaching natural science subjects Dubo Svetlana Ivanovna teacher of biology and chemistry MBOU K-E Secondary School No. 5 November 2013 “An educated person is one who knows where to find what he does not know” G. Simmel
Master class “Possibilities of using a digital microscope in a teacher’s classroom and extracurricular activities” Purpose: to show the possibilities of using a digital microscope at various stages of a lesson and project research activities in the context of the implementation of the Federal State Educational Standard.
Advantages of a digital microscope: Study the object under study not for one student, but for a group of students at the same time, because information can be displayed on a computer monitor; To study an object in dynamics, for example, one of the advantages of a microscope is the ability to conduct video recording to display intermediate stages of long-term experiments when it is not possible to show transformations in real time, for example, the process of seed germination. It can also be used to demonstrate the movements of various objects. Using a digital microscope, you can obtain video recordings of living objects. Create presentation photos and videos on the topic being studied; write captions for drawings and photographs; Use images of objects on paper.
Application of a digital microscope for knowledge control.
Knowledge test 1 2 3
Using a digital microscope in the process of studying new material TYPES OF LEAF VENATION
L/R “Study of onion skin cells”
Practical work "Structure of molds." Purpose of the work: to introduce students to the characteristic features of the structure of molds. Equipment: digital microscope microspecimen "Mold mukor"; computer Instruction card.
2. Examine the mushroom at low and high magnification 3. Take a photograph of the mushroom at low and high magnification 4. Save the drawing in your folder called “Mukor”, 5. Present the results of your work to the whole class using a digital microscope.
Mucor mold 1.
Practical work “Features of the structure and life of mollusks.” Purpose of the work: to introduce students to the characteristic features of the structure and life of mollusks. Equipment: digital microscope, Petri dishes with shells and live mollusks, computer Instruction card. 1. Turn on the computer and launch the program for working with the digital microscope. 2. Examine the object at low and high magnification. Note the shape and color of the mollusks. Draw and label what you see. 3. Pay attention to the way the mollusks move on the glass and paper. 4. Take a photograph of the mollusk under magnification. make a video 5. Save the drawing and video in your folder called “Clams” 6. Present the results of your work to the whole class using a digital microscope Using a digital microscope at the stage of consolidating knowledge.
L/r “Comparison of plant and animal cells”
Study of the external structure of a butterfly, butterfly wing
A report on the work done can be presented in several forms. First option: students print out photographs with captions of objects, paste them into a laboratory journal, and answer questions for the conclusion. The second option: the children save the results of their work on the computer in their personal folder, and the teacher checks the correctness of the signatures and answers to questions for the next lesson. Third option (combined): conclusions are submitted in written form, and drawings are saved on the computer.
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Internet resources: http://site/shkola/biologiya/library/elektronnyy-mikroskop http://yandex.ru/clck/jsredir?from=yandex.ru%3Byandsearch%3Bweb%3B%3B&text= using%20digital%20microscope% 20at%20lessons%20biology& uuid =&state=AiuY0DBWFJ4eP http://lib2.podelise.ru/docs/92891/index-2865.html http://www.myshared.ru/slide/9958/ http://www.proshkolu .ru/user/marina2071/file/2278775/
Preview:
Using a digital microscope in biology lessons
Target:
Introduce master class participants to the possibilities of using a digital microscope in biology lessons
Tasks:
- Learn how a digital microscope works.
- Learn the rules of working with a microscope.
Stage 1 (theoretical)
The appearance of a digital microscope in school not only allows students to see something new, but above all helps the teacher to competently organize classroom and extracurricular activities.
Digital microscope- This is an optical device adapted for work in school conditions, equipped with a converter of visual information into digital information. It provides the ability to transmit to a computer in real time an image of a micro-object and a micro-process, its storage, incl. in the form of digital video recording, display on screen, printing, inclusion in a presentation. With the use of a digital microscope, it became possible to conduct lessons more efficiently and interestingly, especially laboratory work, and interest in biological science and research activities increased, since working with a microscope is one of the most favorite activities among students.
Using a digital microscope in a biology lesson
Changes taking place in the field information technologies, form a new culture of working with information. A digital microscope allows you to:
- study the object under study not for one student, but for a group at the same time, since the information can be displayed on a computer monitor;
- use multi-level tasks for students of the same class;
- study an object in dynamics;
- create presentation videos on the topic being studied;
- use images of objects on paper as handouts.
The use of a digital microscope in conjunction with a computer allows you to obtain an enlarged image of a biological object on the monitor screen of a personal computer or on a large screen using a projection device connected to the computer.
The use of a digital microscope when studying biology saves teaching time, helps to increase the efficiency and informativeness of the lesson and the transition from reproductive transfer of knowledge to intensive creative discussion with students, conducting joint research, and carrying out independent research projects of varying levels of complexity. Application modern technologies makes it possible to solve the problem of training educated people, free from stereotypes, able to quickly navigate the environment and think independently.
Research activities can be implemented not only in biology lessons, but also in extracurricular activities. The program of elective courses goes beyond basic education and includes a large number of practical and laboratory work, the implementation of which using a digital microscope will allow schoolchildren to feel like researchers in one or another area of biology.
Using a digital microscope in biology lessons
Equipment for classrooms computer equipment and its use in the classroom are becoming mandatory attributes of the 21st century school. A digital microscope will help you effectively use a computer in biology lessons. Let's look at specific examples.
- Application of a digital microscope for knowledge control.In order to involve the whole class, the survey must be interesting to the students. This can be achieved if a known factual material viewed in a new light, and theoretical knowledge applied in practice. So, one student can complete the assignment, and the whole class will have the opportunity to see the results of the work, ask questions and make adjustments. This is how collective cognitive activity is realized, during which the knowledge of all students is improved and several people have the opportunity to immediately receive grades.
- Using a digital microscope in the process of studying new material.There are several options for using a microscope here.
1) First option: collaboration teachers and students in the process of demonstrating the object. At the same time, the teacher, demonstrating the drug, explains new material, indicates to students what to pay attention to, asks questions.
2) Second option: self-study microslides by students using the textbook text. The teacher controls and directs the activities of the students.
3) Third option:When studying a complex microspecimen, the teacher first explains the structural features of this object by displaying a microslide on the screen, and then each student independently studies the microslide at the workplace, using instructional cards.
- The use of a digital microscope at the stage of consolidating knowledge.Here, schoolchildren can be asked to compare two studied objects. The result of this work may be the creation of special presentation materials.
The use of a digital microscope in biology lessons gives a tangible pedagogical effect in terms of creating motivation for studying educational material, systematizing and deepening students' knowledge, developing their abilities to acquire and assimilate knowledge. However, the use of computer technologies in the educational process presupposes the presence of three main components: a hardware and software basis (computer and digital microscope), a trained teacher and electronic educational tools available for use.
What does a digital microscope give to teachers and students in relation to biology lessons?
One of the biggest challenges for a biology teacher when conducting laboratory work with a traditional microscope is the virtually impossible ability to understand what his students are actually seeing. How many times do the guys call for something completely wrong - in the field of view is either the edge of the drug, or an air bubble, or a crack...
It is good if there are trained assistants to carry out such mandatory work according to the program. And if you are alone - for 20 people and 10 microscopes? And the microscope standing in the middle of the desk (one for two!) cannot be moved - otherwise all the light and sharpness settings will be lost, and the results of the work (as well as time and interest) will be lost.
It is also important that you can indicate and sign parts of the drug by putting together a slide show from these frames.
This can be done both immediately during the lesson and in the process of preparing for it.
Objects of study can be flower parts, leaf surfaces, root hairs, seeds or seedlings. And mold - even mucor or penicillium? For arthropods, these are all their interesting parts: legs, antennae, mouthparts, eyes, integument (for example, butterfly wing scales). For chordates - fish scales, bird feathers, wool, teeth, hair, nails, and much, much more. This is not a complete list.
It is also important that many of these objects, after research organized using a digital microscope, will remain alive: insects - adults or their larvae, spiders, mollusks, worms can be observed by placing them in special Petri dishes. And any indoor plant easily becomes an object observations and research, without losing a single leaf or flower. This is possible due to the fact that the top part of the microscope is removable, and when brought to an object it works like a webcam, giving 10x magnification. The only inconvenience is that focusing is done only by tilting and zooming in and out.
But, having caught the desired angle, you can easily take a photograph without reaching for the computer - right on the part of the microscope in your hands, there is the necessary button: press once - you get a photo, press and hold - a video is taken.
The use of a digital microscope in biology lessons allows you to increase interest in the subject, improve the quality of learning, reflect the essential aspects of biological objects, embodying the principle of clarity, and bring to the fore the most important (from the point of view of educational goals and objectives) characteristics of the studied objects and natural phenomena.
The material obtained using a digital microscope can be used both in the educational process and in extracurricular activities (club, elective course, elective course).
Stage 2 (practical)
Conducting laboratory work (two groups of participants worked)
Laboratory work
Subject: "Structure of mold fungi."
Goal of the work:
Equipment:
Progress.
1. Turn on the computer and launch the program for working with a digital microscope.
2. Place the specimen under a microscope at 10* magnification using lighting.
3. Examine the mushroom at magnifications of 60* and 200*.
4. Take a photograph of the mushroom at a magnification of 60* and 200*.
6. Present the results of your work to the whole class using a digital microscope.
Laboratory work
Subject:
Target:
Equipment:
Progress:
1. Turn on the computer and launch the program for working with a digital microscope.
4. We take a photograph of the mollusk at magnifications of 20* and 100*, and shoot a video.
Participants first worked independently in pairs using a digital microscope. Then each group demonstrated the results of their activities to all participants of the master class. During the demonstration, the objects were visible to everyone and you can indicate what the guys should have seen through the microscope.
Stage 3
Presentation of your work on a digital microscope (presentation)
Laboratory work
Subject: "Structure of mold fungi."
Goal of the work: To introduce students to the characteristic features of the structure of molds.
Equipment: digital microscope, microspecimen "Mold mukor", computer
Progress.
1. Turn on the computer and launch the program for working with a digital microscope.
2. Examine the mushroom at low and high magnification
3. Take a photograph of the mushroom at low and high magnification
5. Present the results of your work to the whole class using a digital microscope.
Laboratory work
Subject: Features of the structure and life of mollusks
Target: introduce students to the characteristic features of the structure and life of mollusks.
Equipment: digital microscope, Petri dishes with shells and live mollusks, computer
Progress:
1. Turn on the computer and launch the program for working with a digital microscope.
2. Examine the object at low and high magnification. Note the shape and color of the mollusks. Draw and label what you see.
3. Pay attention to the nature of the movement of mollusks on glass and paper. What mark remains on them?
4. Take a photo of the mollusk at magnification and shoot a video.
5. Save the drawing and video in your folder called “Clams”
6.Present the results of your work to the whole class using a digital microscope.
INTRODUCTION
With the help of a digital microscope, you are immersed in a mysterious and fascinating world, where you can learn a lot of new and interesting things. Children, thanks to a microscope, better understand that all living things are so fragile and therefore you need to treat everything that surrounds you very carefully. A digital microscope is a bridge between the real ordinary world and the microworld, which is mysterious, unusual and therefore surprising. And everything amazing attracts attention, affects the child’s mind, develops creativity, love for the subject, and interest in the world around him.
Children meet each task using a microscope with delight and curiosity. It turns out that they are very interested in seeing cells, human hair, leaf veins, fern spores, and mucor mold in an enlarged form.
Chapter 1. USE OF MAGNIFYING DEVICES IN BIOLOGY LESSONS
Magnifier- the simplest magnifying device. Its main part is magnifying glass, convex on both sides and inserted into the frame. Using a magnifying glass, we see an image of an object magnified by 2-25 times. The magnifying glass is taken by the handle and brought closer to the object at a distance at which the image of the object becomes clearest.
Microscope- this is a device that magnifies the image of an object several hundred and even thousand times 15. The first microscopes began to be manufactured in the 17th century. The most advanced microscopes at that time were those designed by the Dutchman Anton van Leeuwenhoek. His microscopes provided magnification up to 270 times. Modern light microscopes magnify images up to 3600 times. In the 20th century An electron microscope was invented that magnifies images tens and hundreds of thousands of times.
The main part of the light microscope you work with in school is magnifying glasses, inserted into a tube, or tube (in Latin, “tubus” means “tube”). At the upper end of the tube there is eyepiece, consisting of a frame and two magnifying glasses. The name "eyepiece" comes from the Latin word "oculus", which means "eye". When examining an object using a microscope, the eye is brought closer to the eyepiece.
At the lower end of the tube is placed lens, consisting of a frame and several magnifying glasses. The name "lens" comes from the Latin word "objectum", which means "object".
The tube is attached to a tripod. An object table is also attached to the tripod, in the center of which there is a hole, and under it a mirror.
Using a microscope, you can examine the cells of all organs of the plant.
Prepare the preparation, place it on the stage and secure the slide there with two clamps.
Using the screw, smoothly lower the tube so that the lower edge of the lens is at a distance of 1-2 mm from the specimen.
While looking through the eyepiece, slowly lift the tube until sharp image subject.
After use, put the microscope into its case.
The microscope includes three main functional parts :
1. Lighting part
Designed to create a light flux that allows you to illuminate an object in such a way that subsequent parts of the microscope perform their functions with extreme precision. The illumination part of a transmitted light microscope is located behind the object under the lens in direct microscopes and in front of the object above lens V inverted. The lighting part includes a light source (lamp and electrical power supply) and an optical-mechanical system (collector, condenser, field and aperture adjustable/iris diaphragms).
2. Reproducing part
Designed to reproduce an object in the image plane with the image quality and magnification required for research (i.e., to construct an image that would reproduce the object with the appropriate optics as accurately as possible and in all details microscope resolution, magnification, contrast and color rendering). The reproducing part provides the first stage of magnification and is located after the object to the microscope image plane.
The reproducing part includes lens and an intermediate optical system.
Modern microscopes of the latest generation are based on optical systems lenses, corrected to infinity. This additionally requires the use of so-called tube systems, which provide parallel beams of light emerging from lens, “collected” in the image plane microscope .
3. Visualization part
Designed to obtain a real image of an object on the retina, photographic film or plate, on the screen of a television or computer monitor with additional magnification (second stage of magnification).
The visualizing part is located between the image plane of the lens and the eyes of the observer ( camera, camera). The imaging part includes a monocular, binocular or trinocular visual attachment with an observation system ( eyepieces, which work like a magnifying glass).
In addition, this part includes additional magnification systems (magnification wholesaler/change systems); projection attachments, including discussion attachments for two or more observers; drawing apparatus; image analysis and documentation systems with corresponding adapter (matching) elements.
Modern microscope consists of the following structural and technological parts:
optical;
mechanical;
electric.
Mechanical part of the microscope
The main structural and mechanical block of the microscope is tripod. The tripod includes the following main blocks: base And tube holder .
Base is a block on which the entire microscope. In simple microscopes, lighting mirrors or overhead illuminators are installed on the base. In more complex models, the lighting system is built into the base without or with a power supply.
Types of microscope bases
base with lighting mirror;
so-called “critical” or simplified lighting;
Keller lighting.
change unit lenses, having the following design options - turret device, threaded device for screwing lens, “sled” for threadless fastening lenses using special guides;
focusing mechanism for coarse and fine adjustment of the microscope for sharpness - mechanism for focusing movement of lenses or stages;
attachment point for replaceable object tables;
mounting unit for focusing and centering movement of the condenser;
attachment point for replaceable attachments (visual, photographic, television, various transmitting devices).
Microscopes may use stands to mount components (for example, a focusing mechanism in stereo microscopes or an illuminator mount in some models of inverted microscopes).
The purely mechanical component of the microscope is stage, intended for fastening or fixing an observation object in a certain position. Tables can be fixed, coordinated and rotating (centered and non-centered).
Microscope optics (optical part)
Optical components and accessories provide the main function of the microscope - creating an enlarged image of an object with a sufficient degree of reliability in shape, size ratio of the constituent elements and color. In addition, the optics must provide an image quality that meets the objectives of the study and the requirements of the analysis methods.
The main optical elements of a microscope are optical elements that form the lighting (including the condenser), observation ( eyepieces) and reproducing (including lenses) microscope systems.
Microscope Objectives
They are optical systems designed to construct a microscopic image in the image plane with appropriate magnification, resolution of elements, and accuracy of reproduction of the shape and color of the object of study. They have a complex optical-mechanical design, which includes several single lenses and components glued together from 2 or 3 lenses. The number of lenses is determined by the range of tasks solved by the lens. The higher the image quality produced by the lens, the more complex its optical design. The total number of lenses in a complex objective can be up to 14 (for example, this could apply to a planochromatic objective with a magnification of 100x and a numerical aperture of 1.40).
The lens consists of front and rear parts. The front lens (or lens system) faces the specimen and is the main one in constructing an image of appropriate quality; it determines the working distance and numerical aperture of the lens. The subsequent part, in combination with the front part, provides the required magnification, focal length and image quality, and also determines the height of the lens and the length of the microscope tube.
Lens classification
The classification of lenses is much more complicated than the classification of microscopes. Lenses are divided according to the principle of calculated image quality, parametric and design-technological characteristics, as well as according to research and contrast methods.
According to the principle of calculated image quality lenses can be:
achromatic;
Beginning of the XXI century takes place under the sign of modernization of school education. New pedagogical technologies, methods, and textbooks are appearing. Information technologies are increasingly being introduced into the educational process. Now computers with projection devices and interactive whiteboards have appeared in many school classrooms. Many biology and chemistry lessons are taught using computer technology.
This article is devoted to the use of a digital microscope in various biology and chemistry lessons.
A digital microscope combines a light microscope and a color digital camera, the optical axis of which coincides with the optical axis of the microscope. A light microscope can be used without a camera, which is installed in place of the eyepiece after adjusting the image. The camera is connected to USB port computer. Software support allows you not only to view objects on the computer screen, but also to take photographs and videos of the objects being studied.
The use of a digital microscope in conjunction with a computer allows you to obtain an enlarged image of a biological object (micropreparation) or crystals on the monitor screen of a personal computer or on a large screen using an external projection device connected to the computer.
When conducting laboratory work in class, a digital microscope provides significant assistance. He has the opportunity:
- study the object under study not for one student, but for a group of students at the same time, since the information is displayed on a computer monitor;
- use pictures of objects as demonstration tables to explain a topic or when questioning students;
- study an object in dynamics;
- create presentation photos and videos on the topic being studied;
- use images of objects on paper.
When all students use light microscopes during laboratory work, the teacher has difficulty in monitoring the correct settings of the students' microscopes - there is simply not enough time to look into each microscope. A digital microscope can solve this problem: the image is displayed on the screen and students have the opportunity to compare what they see on their microscope with the image on the screen, as a result, only some students need to be given real help.
How does it go? laboratory work using a digital microscope?
Stages of laboratory work:
- setting goals and objectives with the help of students;
- explanation of the structure of an object using its image displayed on a large screen;
- independent work students with microscopes (individually or in pairs), while the image with big screen removed;
- sketching the object seen, answering questions, recording conclusions;
- comparison of your drawing with the standard (on the screen).
It must be said that working with a microscope is one of the most favorite activities among students of all ages. Using a digital microscope makes it even brighter, more memorable, and the teacher himself enjoys such work.
When preparing for work, reference images can be created in advance by photographing the desired objects. By the way, the number of such images increases significantly over time, so we recommend that you immediately create several folders on your computer (“Botany”, “Zoology”, “Human” or others) and then immediately sort the photos into thematic folders.
Using a digital microscope, we obtained video recordings of living objects: slipper ciliates, common amoeba, nematodes, rotifers and others. These recordings were also used during lessons.
In conclusion, we note that the use of a digital microscope gives a tangible pedagogical effect in terms of creating motivation for studying educational material, systematizing and deepening students’ knowledge, developing their abilities to acquire and assimilate knowledge, acquiring and consolidating students’ independent research skills.
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