MTC

Question 1

use of cryo-based methods

Answer 1

rapid microscopic analysis
rapid diagnosis
oncologic sx

Question 2

reasons to perform cryo-based methods

Answer 2

Provide quick gross or microscopic diagnostics to identify an unknown
pathologic process, determine disease extent/margins, detect
metastases, or simply identify a tissue.
* Process tissue to give appropriate and accurate diagnosis and
prognosis, as well as to follow research and particular study protocols.
* Confirm the presence of diseased tissue on permanent sections for
diagnosis.

Question 3

Reasons not to perform cryo-based methods

Answer 3

The diagnosis of a frozen segment has no immediate ramifications for
decision making.
* Tissue is required for permanent processing (it is unusual or small, or
it requires lengthy research to diagnose).
* Frozen sections are known to exhibit severe artifacts that make
appropriate interpretation difficult.
* Tissue is severely calcified and ossified.
* The possibility of a major infection (e.g. HIV, hepatitis B/C, TB)

Question 4

arrange

1. Tissues are placed on dispensing
   slide
2. Wells are frozen with chuck and
   over-chuck
3. Applying embedding medium
4. Tissues are placed in embedding
   wells
5. Block is removed for trimming/
   staining
6. Wells are filled with embedding
   media

Answer 4

3 1 4 6 2 5

Question 5

While awaiting the stain line,
prepared slides should be
immediately immersed in formal
alcohol, 95% alcohol (methanol /
ethanol), or formalin; if this step is
skipped, ___ artifacts will occur

Answer 5

drying

Question 6

use of IHC

Answer 6

tumor

Question 7

IHC flowchart

Answer 7

deparaffinization
rehydration
Ag retrieval
blocking
primary antibody
secondary antibody
chromogen application
counterstain

Question 8

For epitopes which may lose antigenicity with heat, may destroy
epitopes and tissue morphology

Answer 8

enzyme digestion

Question 9

used method For some drugs such as bleomycin, daunomycin and pepleomycin

Answer 9

oxidizing

Question 10

used to Minimize contamination of sections

Answer 10

detergent

Question 11

Background staining can be caused by:

Answer 11

1. nonspecific antibody binding - more common in polyclonal antibodies, and
2. endogenous peroxidase activity - more problematic in tissues with a high
   concentration of hematopoietic components, (e.g. bone marrow)
3. Nonspecific antibody binding can be reduced by:
   > Preincubating the secondary antibody with normal serum from the same species or with
   a commercially available universal blocking agent (e.g. goat serum).

Question 12

targets a single epitope; tends to be more specific

Answer 12

monoclonal antibody

Question 13

can bind many different epitopes; tends to be more sensitive

Answer 13

polyclonal antibody

Question 14

function of the secondary antibody

Answer 14

visualize the antigen-antibody reaction

Question 15

How can nonspecific antibody binding be reduced

Answer 15

preincubating the secondary antibody with normal serum from the same species or with a commercially available universal blocking agent

Question 16

causes of background staining

Answer 16

1. nonspecific antibody binding
2. endogenous peroxidase activity

Question 17

goal of fixation

Answer 17

preservation

Question 18

most common type of fixation

Answer 18

immersion

Question 19

selection of fixative should be based on

Answer 19

1. prevent degeneration and autolysis
2. can harden to enable cutting
3. does not distort the cellular constituents
4. can support chemicals used in processing

Question 20

optimum size and thickness for trimming

Answer 20

size: 2x2x0.3cm
thickness: 3-4 mm

Question 21

Aim of tissue processing

Answer 21

embed the tissue in a solid medium firm enough to support the tissue and give it sufficient rigidity to enable thin sections to be cut

Question 22

stages of tissue processing

Answer 22

1. dehydration
2. clearing
3. impregnation
4. embedding

Question 23

Standard / best example for clearing medium

Answer 23

Xylene

Question 24

best example for dehydrating fluid/ agent

Answer 24

ethanol

Question 25

Preferred embedding medium

Answer 25

paraffin wax

Question 26

melting point of paraffin wax

Answer 26

52-56 degrees celsius

Question 27

plastic point (point of solidification)

Answer 27

10 degrees below melting point

Question 28

precision instrument that cuts sections from the paraffin blocks, thin enough for examination under microscope

Answer 28

microtome

Question 29

basic principles of staining

Answer 29

1. deparaffinization 2. hydration 3. washing and rinsing

Question 30

Routine staining

Answer 30

hematoxylin and eosin stain

Question 31

what does the following stain in an H&E stain nuclei cytoplasm muscle fiber RBC calcium mucin

Answer 31

nuclei - blue cytoplasm - pink/purple muscle fiber - deep red RBC - orange-red calcium - dark blue mucin - gray-blue

Question 32

Van Gieson stain differentiates ___ and ___

Answer 32

collagen and other connective tissues

Question 33

Van Gieosin stain: collagen: ___, muscle fiber and blood cells: ___

Answer 33

collagen: red muscle fiber and blood cells: yellow

Question 34

toluidine blue is attracted to ______

Answer 34

nucleic acids

Question 35

toluidine blue: nucleic acid:_____, mucin & cartilage: _______

Answer 35

nucleic acid: blue mucin & cartilage: purple

Question 36

Masson's trichrome stain: nuclei: cytoplasm, muscle, erythrocyte: collagen:

Answer 36

nuclei: black cytoplasm, muscle, erythrocyte: red collagen: blue/green

Question 37

PAS (Periodic Acid Schiff) differentiates ____. PAS positive:___ nuclei:

Answer 37

glycogen PAS positive: pink or red nuclei: blue