31 Jul In book: Shafer’s Textbook of Oral Pathology: 7th Edition, Edition: 7 th Edition, Chapter: Routine Histotechniques, Staining and Notes on. 5 Mar Histology refers to the study of microscopic structures in biological material and its ways where individual components are both structurally and. Histology Lab, Biology Spring Dr. Ed Devlin. Webpage for Course: Lab Topic.
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Alcohols, specifically ethanol, are used primarily for cytologic smears. Vena cava human c. The tissue sample now surrounded by hard paraffin is trimmed to a trapezoid shape and placed in the chuck of a microtome. There histotechniquds trade-offs in dehydration as in all the other steps. The sections are then ready for staining. Toluene is the best solvent for this purpose. Never use the substage diaphragm to control the intensity of light.
Knife rings as it passes over tissue. This “embedding” process is very important, because the tissues must be aligned, or oriented, properly in the block of paraffin.
Any aberrations in the design and construction of the lenses. Pyloric stomach primate sec. Histoetchniques this tree is very rare nowadays, most hematein is of the synthetic variety. A product called paraplast contains added plasticizers histotechniqhes make the paraffin blocks easier for some technicians to cut. It should stabilize carbohydrates, lipids, proteins and nucleic acids to prevent them from being dissolved or redistributed during subsequent processing.
Although the nucleus and chromosomes are generally rendered easily stainable. Some of them have specialized applications, but are used very infrequently. With a progressive stain the slide is dipped in the hematoxylin until the desired intensity of staining is achieved, such as with a frozen section. Fixation – factors affecting fixation There are a number of factors that will affect the fixation process: The problem arises when, during embedding, not all the tissue is removed from the cassette.
Contamination of clearing agents or coverslipping media may also produce a bubbled appearance under the microscope.
The glutaraldehyde must be cold and buffered and not more than 3 months old. Cleared specimens are placed in a solution of molten paraffin in an oven set at about uistotechniques o C.
Esophagus and stomach l. The presence of large irregular clumps of black precipitate on slides of tissues fixed in a mercurial fixative such as B-5 suggests that the tissues were histtoechniques “dezenkerized” prior to staining.
Sectioning Once the tissues have been embedded, they must be cut into sections that can be placed on a slide. Bouin’s fluid histotechniqued proteins. Once sections are cut, they are floated on a warm water bath that helps remove wrinkles.
Areolar tissue spread film 6. Force yourself to integrate information from discrete observations and develop generalizations about the cells and intercellular substances under consideration. He will remove it with lacquer thinner.
It is a somewhat messy procedure; the oil must be carefully removed when you are through.
Do not get in the habit of adjusting the intensity with the substage diaphragm vide infra. Histology Lab, Biology Fundic stomach primate sec.
Sectioning is the most difficult part of the tissue preparation process and you should read chapters 4 and 5 in Humason before signing up to do your sectioning.
Mammary gland inactive human sec. We will demonstrate this procedure.