How do you process tissue specimen by using a freezing microtome?
The microtome can be compared to a very accurate “deli” slicer, capable of slicing sections as thin as 1 micrometre. The usual histology slice is cut at 5 to 10 micrometres. The surgical specimen is placed on a metal tissue disc which is then secured in a chuck and frozen rapidly to about –20 to –30 °C.
What is the procedure of H&E staining?
The H&E staining method involves application of haematoxylin mixed with a metallic salt, or mordant, often followed by a rinse in a weak acid solution to remove excess staining (differentiation), followed by bluing in mildly alkaline water.
Why do we do frozen sections?
The frozen section is mainly used for rapid diagnosis of the lesion for intraoperative management, to know the extent of the lesion, to do enzyme immunocytochemistry and immunofluorescence study and also to stain lipid and certain carbohydrate in the tissue.
How do you Destain H&E slides?
Clinically, we de-stain H&E slides as a regular protocol using 1:1 Xylene/Acetone solution to remove the coverslip and 1% Acid (HCl) Alcohol to remove the stains. Acid alcohol is used in regressive hematoxylin staining regularly and eosin is quickly removed by both acetone and alcohol.
What is routine H & E?
In the histopathology laboratory, the term “routine staining” refers to the hematoxylin and eosin stain (H&E) that is used “routinely” with all tissue specimens to reveal the underlying tissue structures and conditions.
When should you use a frozen section?
How is each of these specimens sent to the pathologist frozen section?
Specimens designated for frozen section must be immediately passed off the sterile field to the circulator and delivered to the pathology department. A. The specimen should be passed off the sterile field by the CST to the circulator using aseptic technique.
Can you do IHC on tissue sections that are already H&E stained?
You can perform the other way around, if you have already stained your tissue with IHC/DAB (not IF).. as said above, depending on you mounting media, soak off the cover slip (xylene if using a hard solvent based mount, PBS/water if using a wet mount) .
Why does xylene go cloudy?
Cloudiness can also occur if the volume of liquids in the alcohol or xylene solution containers are not leveled to the proper depths.
What will be the color of the following if the tissue is stained with H & E?
Hematoxylin has a deep blue-purple color and stains nucleic acids by a complex, incompletely understood reaction. Eosin is pink and stains proteins nonspecifically. In a typical tissue, nuclei are stained blue, whereas the cytoplasm and extracellular matrix have varying degrees of pink staining.
What do you do with a frozen section?
Press a glass slide firmly over the section and fix immediately in methanol for 1 minute. 95 percent ethanol can also be used for tissue fixation (for a few seconds). Rapid fixation is a must as a delay results in swollen cells and hazy cell margins.
What are mast cells?
Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells were discovered by Paul Ehrlich in 1877.
Why are mast cells coated with immunoglobulin E?
This receptor is of such high affinity that binding of IgE molecules is in essence irreversible. As a result, mast cells are coated with IgE, which is produced by plasma cells (the antibody-producing cells of the immune system).
How do mast cells activate T cells?
When mast cells are stimulated through TLF-7, they release IL-1 and TNFα, which causes dendritic cells to move from their location in the skin and go to local lymph nodes and activate cytotoxic T cells. Additionally, mast cells release TNFα, which can activate cytotoxic T cells directly (30).