From Specimen to Slide Flashcards
Collected tissues should be fixed in a ____% ________________ solution.
10% Neutral Buffered formalin
What is the minimum formalin to tissue ratio needed?
Formalin: Tissue ratio should be 10:1 or greater (Volume of formalin must be at least 10x that of the tissue in the jar)
Why is it important to have a proper formalin to tissue ratio when fixing your tissues for histopath?
A. Inadequate volume will not allow saturation of the tissue, and poorly fixed tissues do not stain well.
B. Fixation by formalin stops autolysis in its tracks.
C. Too much formalin will autolyse the tissue.
D. Fixation changes the refractive index of tissues, allowing for contrast to be seen.
E. All except 1 of the above are true (which one?)
E.
Too much formalin will nnot autolyse tissues.
Formalin fixes at a rate of ____/hr and a minimum of ______hrs is recommended for fixation of tissue in formalin prior to processing.
1mm/hr
24 hrs
What are the 2 different fixatives used to harden autolyzed and neural tissues, especially recommended for eye, fetal tissue, and uterine biopsies?
Bouin’s and Davidson’s
Which of the following is NOT true of fixation of tissue in formalin?
A. Intestinal tissue should be cut open and its contents should be removed before fixation
B. Submitted tissue should contain lesioned and normal tissues.
C. Large masses should be “breadloafed”
or cut into sections less than 1 cm in size.
D. You must maintain the 10:1 formalin to tissue ratio when fixing tissue in formalin jars.
E. If the formalin in the jar is bloody or has other organic material in it, it needs to be changed after 24 hours.
F. All of the above are true.
F.
T or F: When taking an endoscopal biopsy, it is highly recommended to get at least 3-4 pieces of tissue to get a representative sample.
False
7-10 pieces.
T or F: Excisional masses should be marked with suture to indicate orientation, and edges should be inked (preferably with different colors) for an accurate margin assessment to be made by the pathologist.
T
When trimming masses, the ideal thickness of the tissue for the cassette is _______
About 3mm (3-5 mm range)
Which of the following is NOT true?
A. Mineralized and keratinized tissues need special treatment before they are trimmed.
B. Bone can be demineralized with a decalcifier
C. Hooves and nails can be dekeratinized using fabric softener
D. Softening of these tissues can be done after trimming.
D. Softening of these tissues must be done BEFORE trimming
What is the correct order of tissue processing?
A. Water in tissue—>Xylene—>Graded alcohols—>paraffin
B. Water in tissue—> Graded alcohols->xylene—>paraffin
C. Water in tissue—>paraffin—>graded alcohols—->xylene
B
Which is the INCORRECT pairing?
A. Xylene: fixative agent B. Graded alcohols: 70%, 95%, 100% C. Paraffin: mixture of plastics and wax D. Xylene: Clearing agent E. Water in tissue: completely replaced by paraffin
A.
Xylene is the clearing agent: clears the alcohol before paraffin is added.
T or F:
Processing can be automated by a machine that uses vacuum pressure to help penetrate the tissues, but the process takes about 24 hours.
False;
The guy’s machine takes 15 hours (about overnight) to process
T or F: The first step to cutting a block of tissue is the rough trim, which involves cutting it 5-30 micrometers, or until the surface of the tissue is exposed.
True
What do you do to the tissue block after it has been rough trimmed?
Put on ice
