Histopath

Question 1

What is microtomy?

Answer 1

Microtomy is the process of trimming and cutting processed tissue into thin slices for microscopic studies.

Question 2

What is the remedy for brittle or hard tissue during tissue processing?

Answer 2

If tissue becomes brittle or hard due to prolonged fixation, soak the tissue in a bowl containing water with phenol.

Question 3

What should be done if the clearing agent turns milky during tissue processing?

Answer 3

If the clearing agent turns milky due to incomplete dehydration, repeat dehydration with absolute alcohol and then clear again.

Question 4

What should be done if wax appears crystalline during trimming?

Answer 4

If wax appears crystalline due to contaminated wax, re-embed the tissue in freshly filtered wax.

Question 5

How to remedy frozen tissue chipping into fragments during cutting?

Answer 5

If tissue chips into fragments when cut due to being too hard from freezing, warm the tissue with the fingers before cutting.

Question 6

What is a Compound Embedding Unit?

Answer 6

A series of interlocking plates resting on a flat metal/rubber base, forming several compartments. Advantage: Embedding more specimens at a time, reducing time needed for blocking.

Question 7

What are the four types of embedding media?

Answer 7

1. Paraffin wax

Question 8

2. Celloidin

Question 9

3. Gelatin

Question 10

4. Plastic

Question 11

What are the three types of Disposable Embedding Molds mentioned?

Answer 11

1. PEEL AWAY

Question 12

2. Paper Boats

Question 13

3. Plastic Ice trays

Question 14

What is an ultrathin microtome used for?

Answer 14

An ultrathin microtome is used for cutting tissues in preparation for electron microscopy, producing sections as thin as 0.5 microns.

Question 15

What are the requirements for specimens in an ultrathin microtome?

Answer 15

Specimens must be small, fixed in osmium tetroxide, and embedded in plastic before being cut.

Question 16

What is the typical thickness of sections cut for routine histologic procedures?

Answer 16

Sections are usually cut between 4-6 microns in thickness for routine histologic procedures.

Question 17

At what angle is the knife usually tilted on a microtome?

Answer 17

The knife is usually tilted at 0-15 degree angulation on a microtome for cutting sections.

Question 18

What is the purpose of an ultrathin microtome?

Answer 18

Cutting tissues in preparation for electron microscopy.

Question 19

What specific size are tissues cut to using an ultrathin microtome?

Answer 19

0.5 micra thin.

Question 20

What type of knife is used in an ultrathin microtome?

Answer 20

Fragments of broken plate glass.

Question 21

What are the essential parts of a microtome?

Answer 21

Block holder, knife carrier and knife, pawl, ratchet feed wheel, adjustment screws.

Question 22

What is a sliding microtome used for?

Answer 22

Celloidin embedded sections.

Question 23

What is staining?

Answer 23

Staining is the process of applying dyes on tissue sections to study architectural patterns and cell characteristics.

Question 24

What is tissue staining?

Answer 24

Tissue staining is the process of demonstrating tissue constituents in sections through direct interaction with dyes or staining solutions.

Question 25

What is metachromasia?

Answer 25

Metachromasia is when dyes stain tissues with a different color from the dye itself.

Question 26

Give examples of dyes that exhibit metachromasia.

Answer 26

Examples of dyes that exhibit metachromasia include Methyl violet, Cresyl blue, Safranin, and Bismarck Brown.

Question 27

How can tissue substances be localized microscopically?

Answer 27

Tissue substances can be localized microscopically through chemical reactions during the staining process.

Question 28

How are various constituents of tissues studied?

Answer 28

Various constituents of tissues are studied through chemical reactions that permit microscopic localization of a specific tissue substance.

Question 29

What is tissue staining a combination of?

Answer 29

Tissue staining is a combination of immunologic and histochemical techniques that allow phenotypic markers to be detected.