Slides for university students are usually prepared in the histology lab. Students in medical sciences are often trained to know what a tissue is when placed on a slide. The essence is for them to be able to identify anomalies or deviations from the standard ones. However, before they can start taking any of the required lectures, the lab technologists must take the tissues through some histology techniques to prepare microscope slides.
The microscopes used are of various types. The students are taught how to view with the light, electron, phase contrast, fluoresce, confocal microscope and others. Some of these are more preferred to others based on the size of the slides and how clear you want it to become. They also differ in various ways.
The parts of a light microscope include the presence of lamp, iris, diaphragm, tube and lenses, eyepiece, adjustment knobs, and objective lens. There are usually three types of adjustment knobs, and they include condenser height, fine and coarse knobs. Their major function is to control the clarity of what is being viewed.
The tissues that will be placed under the microscope must be processed before they can be used. There are different techniques to do this and they include fixation, dehydration, clearing, waxing, embedding, and staining. The use of chemicals applies in these steps and they have to be in the required amount if the tissue is going to be well prepared or last long.
Fixation is the first step to take after the death of a cell. It is done to prevent decay since tissues start breaking down immediately after death. The dead tissue is soaked in fixatives such as buffered formalin, Bouin's fluid, and salt. Other ways to prevent decay of tissues after death are refrigeration and heating. When applying fixatives, the ratio should be 3 volumes of fixatives to 1 volume of tissue. This volume must be maintained to make sure the whole tissue is covered.
Fixation usually introduces water that must be removed through the process called dehydration. Since alcohol and water are miscible, alcohol can be used in the process. The concentration of alcohol used should vary from low to high and in an ascending order. It is good to do it with 50%, 50%, 75%, 75%, 98%, and 98% alcohol concentrations one after the other. This is necessary to remove all bubbles and to prevent the possibility of shrinking.
After dehydrating the tissue, the alcohol has to be removed and this can be done by the process called clearing. It can be done with clearing agents such as xylene, benzene, toluene, and chloroform. Afterward, impregnate with wax to remove xylene. Apart from removing the xylene, waxing makes cutting easy and the quality of the cuts to be strong.
Dewaxing must be done in the end. In dewaxing, the tissue has to be rehydrated so as to bring it back to water. Rehydrating is done with alcohol, but this time in descending grades. You can start with 98% alcohol and stop with 50% alcohol. Of course, water will also be used in this process. The tissues are then stained with some special dyes such as Periodic Acid Schiff, Van Gieson, Masson trichrome, Sudan black, and Osmium tetroxide.
The microscopes used are of various types. The students are taught how to view with the light, electron, phase contrast, fluoresce, confocal microscope and others. Some of these are more preferred to others based on the size of the slides and how clear you want it to become. They also differ in various ways.
The parts of a light microscope include the presence of lamp, iris, diaphragm, tube and lenses, eyepiece, adjustment knobs, and objective lens. There are usually three types of adjustment knobs, and they include condenser height, fine and coarse knobs. Their major function is to control the clarity of what is being viewed.
The tissues that will be placed under the microscope must be processed before they can be used. There are different techniques to do this and they include fixation, dehydration, clearing, waxing, embedding, and staining. The use of chemicals applies in these steps and they have to be in the required amount if the tissue is going to be well prepared or last long.
Fixation is the first step to take after the death of a cell. It is done to prevent decay since tissues start breaking down immediately after death. The dead tissue is soaked in fixatives such as buffered formalin, Bouin's fluid, and salt. Other ways to prevent decay of tissues after death are refrigeration and heating. When applying fixatives, the ratio should be 3 volumes of fixatives to 1 volume of tissue. This volume must be maintained to make sure the whole tissue is covered.
Fixation usually introduces water that must be removed through the process called dehydration. Since alcohol and water are miscible, alcohol can be used in the process. The concentration of alcohol used should vary from low to high and in an ascending order. It is good to do it with 50%, 50%, 75%, 75%, 98%, and 98% alcohol concentrations one after the other. This is necessary to remove all bubbles and to prevent the possibility of shrinking.
After dehydrating the tissue, the alcohol has to be removed and this can be done by the process called clearing. It can be done with clearing agents such as xylene, benzene, toluene, and chloroform. Afterward, impregnate with wax to remove xylene. Apart from removing the xylene, waxing makes cutting easy and the quality of the cuts to be strong.
Dewaxing must be done in the end. In dewaxing, the tissue has to be rehydrated so as to bring it back to water. Rehydrating is done with alcohol, but this time in descending grades. You can start with 98% alcohol and stop with 50% alcohol. Of course, water will also be used in this process. The tissues are then stained with some special dyes such as Periodic Acid Schiff, Van Gieson, Masson trichrome, Sudan black, and Osmium tetroxide.
About the Author:
When you are searching for information about microscope slides, come to our web pages today. More details are available at http://www.greengeological.com/shop/category/35-microscope-slides now.
Posts
0 comments:
Post a Comment