Microscopes

This movement is called "bobbing" and it helps to visually focus the image by moving the stage or body of the microscope closer to or farther away from the objective lens. It allows you to bring the specimen into sharp focus by adjusting the distance between the objective lens and the specimen.

An electron microscope bombards its target with electrons, while a traditional microscope uses visible light. Electrons can be resolved at considerably higher magnifications that visible light (due to their smaller wavelength).

A simple microscope uses light to magnify and has only one lens. These microscopes are commonly used in schools for educational purposes and have a lower magnification power compared to compound microscopes.

When storing a microscope, first clean it thoroughly to remove any debris or oils. Next, cover it with a dust cover or place it in its storage case. Store it in a cool, dry place away from direct sunlight and fluctuations in temperature. It's also a good idea to remove any batteries to prevent corrosion.

Microscopes work on the principle of magnifying light rays passing through a tiny object. The object should be transparent or translucent and colored to be properly viewed under a compound microscope. Some of the mandatory requirements to prepare a good slide for viewing are as follows:

Before creating a smear, always check that the slide is clean and perfectly transparent. It should also be microbe free. So, take a slide and wash it first with soap-water, and then wipe it with ethanol (ethyl alcohol). This makes the slide clean and sterilized.

With regard to preparing a slide of bacterial specimen, when you create a smear, do not make a thick layer of smear. Take very little quantity of the inoculum. If by chance you take too much of the inoculum, spread it over the slide to a larger area, such as to avoid a thick smear.

Air drying is necessary, as it lets the bacteria congregate at their places. Heat fix the slide with precision. Too much heat fix can kill the organism, and too little of it will make the organisms too loosely bound to the slide surface. If they are loosely bound, they will fall off when you flood the slide with stain. One good way of identifying the extent of heat fix is to feel it after you pass the slide through the flame. It should neither be too hot nor warm. It should give you the sense of heat but tolerable.

When you stain the slide, do not stain the whole surface of the slide. This wastes much of the stain and is messy. Cleanliness is very important in all science experiments. Just staining the area containing the smear is enough. Usually, stainings are done for a minute or two, but for certain experiments like endospore staining, the extent of staining time may be as long as 10 mins or even more. During such cases, ensure that the stain does not dry over the smear. Maintain liquidity of the stain, as it is to be washed after some time.

While washing the slide after staining, do not let the water stream fall directly on the smear. This may disrupt the smear. Let the stream of water flow slowly along the surface, such that only the stain is flooded and the smear is intact.

While preparing fungal slides, take the stain first, and then the hyphal fragments. Crush the hyphal fragments properly by placing a coverslip over the fragments (avoiding air bubbles) and the slowly tapping it with the butt of a pencil.

Always observe under 10X first. This will give you an idea of the location of a good area for observation. After this, you may prefer to switch over to 45X.

100X objective in compound microscopes is always used as an oil-immersion objective, so do not ever observe at a specimen at 100X without oil.

An electron microscope uses a beam of electrons to illuminate a specimen, providing higher resolution images than a light microscope. It can magnify structures up to 2 million times, allowing for detailed examination of small objects at the molecular and atomic levels.

There are many types of lab apparatus and safety precautions differ greatly for the different types. Here are some general rules.

* Always wear proper eye safety gear in the lab. Safety goggles should cover the eyes completely. Regular glasses cannot be used instead of safety goggles.

* You should have a separate container for broken glass. Never throw away glass in a regular trashcan where it can cut open the bag and cause an injury.

* For fast moving equipment like centrifuges, make sure that all parts are secure and balanced before operating.

* Be careful when handling mercury thermometers. Learn how to take care of mercury spills in the lab you are in. Most labs have a mercury spill kit in the building if not in the lab.

* Watch out for bottles of solvents (such as dichloromethane) that have a top designed to let you squeeze the solvent conveniently for cleaning purposes or heavy use. After use these often build up pressure due to low vaporization temperatures and can squirt their contents after being set down towards you, another person, or your reaction.

* When dealing with open flame be sure to know about the fire safety guidelines of your lab. Also, be sure to clear the area of any flammable objects including bottles of flammable solvents.

* Try not to work alone in the lab. It is always better to have a safety buddy who is familiar with a lab setting and knows the proper safety guidelines.

* When dealing with apparatus that either creates a vacuum or exerts pressure be sure to make sure everything is in working order and remember that such apparatus have the potential to explode.

Rotating the body tube on a microscope allows for easy sharing of the view between multiple users without having to move the entire microscope. It can also be useful for adjusting the eyepieces to a comfortable position for different users.

The slide is placed on the stage of the microscope. It is typically secured in place using stage clips or a mechanical stage. The slide should be positioned so that the region of interest is centered over the light source to enable clear viewing.

MP=(d/L)*(1-(L-l)f)

where d would be the distance from the eye to the image without a lens

L is the distance from the eye to the new virtual image (with a lens)

l is the distance from the eye to the lens

this equation only covers a single lens (whereas there tend to be two in a microscope), but that's no worry; use it twice!

(i.e treat both lenses as independent sources of the image)

The optical parts of a compound microscope include the eyepiece (ocular lens), the objective lens, and the condenser. The eyepiece magnifies the image, the objective lens collects light from the specimen, and the condenser focuses light onto the specimen.

To center the image in the microscope, you would need to move the slide downwards and towards the left. This movement will bring the off-centre image towards the center of the field of view. Remember to adjust the slide carefully to avoid damaging the microscope or the specimen.

The compound microscope is important because it allows for magnification of small objects that are otherwise invisible to the naked eye. It is essential for various fields such as biology, medicine, and materials science to study cells, bacteria, tissues, and other microscopic structures in detail. The compound microscope has greatly advanced scientific research and discovery by enabling scientists to delve deeper into the world of the extremely small.

Anton Van Leeuwenhoek was the first to observe living single-celled organisms, known as microorganisms or bacteria, through his simple microscopes in the 1600s. This discovery revolutionized the field of microscopy and our understanding of the microbial world.

Hematoxylin is only the drastic substance that these solutions contain. For histology, the two most commonly used are Mayer's Hematoxylin and Harris' Hematoxylin. They both contain water, hematoxylin and various salts.

Electron microscopes work by reflecting electrons from the sample to build an image. This achieves a higher degree of magnification than conventional microscopy which uses reflected photons (light) to build a magnified image. However, samples which are often viewed under an electron microscope (particularly biological samples) would not reflect the electrons by themselves, but would allow them to pass straight through. Coating the sample with a conductive metal ensures that the electrons are reflected by the coated sample so that a magnified image can be built up

Living things typically exhibit characteristics such as growth, reproduction, response to stimuli, metabolism, and organization. Look for traits like movement, respiration, sensitivity, and the ability to adapt to the environment to help determine if an object is a living thing.

Both electrons and light exhibit properties of wave-particle duality, meaning they can behave as particles or waves depending on the situation. They both have energy associated with them – electrons have kinetic energy and potential energy, while light has energy determined by its wavelength. Both are crucial in the field of quantum mechanics and have fundamental roles in the behavior and interactions of matter.

The stage on a microscope is typically moved using coarse and fine adjustment knobs located on the mechanical stage assembly. These knobs allow the user to move the stage up and down or side to side to adjust the position of the specimen for viewing.

The compound microscope was made by a Dutch spectacle maker named Zacharias Janssen in the late 16th century. He is credited with creating the first compound microscope by combining lenses in a tube to magnify objects.

The resolving power of an electron microscope is typically between 0.1 to 0.3 nanometers, which is much higher than that of a light microscope. This allows electron microscopes to visualize structures at the atomic level.

The eyepiece lens of a compound microscope acts essentially a low power (x10 or so) magnifier of the real image created by the objective lens.

Burlington NC Under the Carolina Biological Supply Company

1. Resolution: Electron microscopes have higher resolution than light microscopes.
2. Magnification: Electron microscopes can achieve much higher magnifications than light microscopes.
3. Wavelength of illumination: Electron microscopes use electrons for illumination, while light microscopes use visible light.
4. Specimen preparation: Electron microscopes require more extensive specimen preparation compared to light microscopes.
5. Depth of field: Light microscopes have a larger depth of field than electron microscopes.
6. Cost and size: Electron microscopes are typically larger and more expensive than light microscopes.