Immunohistochemistry

Question 1

what is IHC

Answer 1

detecting antigens (proteins) in cells of a tissue by using a specific antigen/antibody reaction tagged with a visible label

Question 2

define immunogen

Answer 2

anything that causes an immune response by stimulating production of antibodies in the host

Question 3

define antibody (immunoglobulin)

Answer 3

Y-shaped protein produced by plasma cells as the result of an immunogen
used by the immune system to neutralize foreign objects

Question 4

define antigen

Answer 4

protein biomarker used to identify and classify cells

Question 5

what is a AE1/AE3 stain used for

Answer 5

stains cytokeratin in cytoplasm
ex. tonsils

Question 6

what does estrogen receptor staining stain

Answer 6

nucleus
ex. breast tissue

Question 7

what does E-cadherin stain

Answer 7

cell membrane
ex. breast cancer

Question 8

what is direct IHC labeling

Answer 8

labeled antibody directly binds with specific antigen in a tissue
fast but has a low intensity since signal isn’t amplified
used for skin and kidney

Question 9

what is indirect IHC staining

Answer 9

unlabeled antibody attached to the specific antigen - secondary antibody attached to primary antibody
longer but is less expensive and more sensitive

Question 10

what does PAP stand for

Answer 10

peroxidase anti-peroxidase - type of indirect IHC staining method

Question 11

what does ABC stand for

Answer 11

avidin-biotin complex - type of indirect IHC staining method

Question 12

what does SP stand for

Answer 12

stretavidin peroxidase - type of indirect IHC staining method

Question 13

what is unique about ABC, SP, and PAP indirect staining methods

Answer 13

they use biotin molecules which amplify the signals

Question 14

what is the polymer-based immunohistochemistry (EnVision) staining technique

Answer 14

uses a polymer backbone and anti-mouse and anti-rabbit antigens

Question 15

what is the immunoenzyme method

Answer 15

enzyme is used as a label
ex. DAB

Question 16

what is the immunofluorescence method

Answer 16

a fluorochrome is used as the label
ex. FITC

Question 17

what is the immunogold method

Answer 17

colloidal gold particles used as the label
ex. EM

Question 18

why are polyclonal antibodies good and bad to use

Answer 18

easier and cheaper to make than monoclonal because they come from so many different animals
but they are less specific than monoclonal

Question 19

why are monoclonal antibodies good and bad to use

Answer 19

difficult to produce and very expensive
but they are highly specific

Question 20

up to how long should paraffin be stored

Answer 20

2 weeks - beyond it loses antigenicity

Question 21

what does the blocking step do

Answer 21

decreases background staining that can be caused by endogenous enzyme and biotin

Question 22

define CUP

Answer 22

carcinoma of unknown primary

Question 23

what does a breast panel test for

Answer 23

ER
PgR
HER2
androgen receptor

Question 24

what does a melanoma panel test for

Answer 24

Mel A and HMB 45

Question 25

what are the Hodgkins lymphoma markers

Answer 25

CD15 and CD30

Question 26

what are the B-cell lymphoma markers

Answer 26

CD 20 and CD 10

Question 27

what are the T-cell lymphoma markers

Answer 27

CD3 and CD 5

Question 28

what is the cell proliferation marker

Answer 28

KI 67

Question 29

what are cytokeratins used for

Answer 29

identification of carcinomas and sarcomas

Question 30

what are alpha-fetoprotiens used for

Answer 30

identify yolk sac tumors and hepatocellular carcinoma

Question 31

what is the CD117 (C-KIT) marker used for

Answer 31

GIST and mast cell tumors

Question 32

what is the CD10 (CALLA) marker used for

Answer 32

renal cell carcinoma and ALL