Immunohistochemistry Flashcards
what is IHC
detecting antigens (proteins) in cells of a tissue by using a specific antigen/antibody reaction tagged with a visible label
define immunogen
anything that causes an immune response by stimulating production of antibodies in the host
define antibody (immunoglobulin)
Y-shaped protein produced by plasma cells as the result of an immunogen
used by the immune system to neutralize foreign objects
define antigen
protein biomarker used to identify and classify cells
what is a AE1/AE3 stain used for
stains cytokeratin in cytoplasm
ex. tonsils
what does estrogen receptor staining stain
nucleus
ex. breast tissue
what does E-cadherin stain
cell membrane
ex. breast cancer
what is direct IHC labeling
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
what is indirect IHC staining
unlabeled antibody attached to the specific antigen - secondary antibody attached to primary antibody
longer but is less expensive and more sensitive
what does PAP stand for
peroxidase anti-peroxidase - type of indirect IHC staining method
what does ABC stand for
avidin-biotin complex - type of indirect IHC staining method
what does SP stand for
stretavidin peroxidase - type of indirect IHC staining method
what is unique about ABC, SP, and PAP indirect staining methods
they use biotin molecules which amplify the signals
what is the polymer-based immunohistochemistry (EnVision) staining technique
uses a polymer backbone and anti-mouse and anti-rabbit antigens
what is the immunoenzyme method
enzyme is used as a label
ex. DAB
what is the immunofluorescence method
a fluorochrome is used as the label
ex. FITC
what is the immunogold method
colloidal gold particles used as the label
ex. EM
why are polyclonal antibodies good and bad to use
easier and cheaper to make than monoclonal because they come from so many different animals
but they are less specific than monoclonal
why are monoclonal antibodies good and bad to use
difficult to produce and very expensive
but they are highly specific
up to how long should paraffin be stored
2 weeks - beyond it loses antigenicity
what does the blocking step do
decreases background staining that can be caused by endogenous enzyme and biotin
define CUP
carcinoma of unknown primary
what does a breast panel test for
ER
PgR
HER2
androgen receptor
what does a melanoma panel test for
Mel A and HMB 45
what are the Hodgkins lymphoma markers
CD15 and CD30
what are the B-cell lymphoma markers
CD 20 and CD 10
what are the T-cell lymphoma markers
CD3 and CD 5
what is the cell proliferation marker
KI 67
what are cytokeratins used for
identification of carcinomas and sarcomas
what are alpha-fetoprotiens used for
identify yolk sac tumors and hepatocellular carcinoma
what is the CD117 (C-KIT) marker used for
GIST and mast cell tumors
what is the CD10 (CALLA) marker used for
renal cell carcinoma and ALL
