IMMUNOHISTOCHEMISTRY_Bruce

Question 1

Controls

: It is always advisable to use

a section that is known and proven to contain the antigen in question because absence of staining in a test section does not necessarily mean that the antigen is absent in the tissue being studied.

Answer 1

Positive Control

Question 2

Controls

: This can be done using a parallel section from the tissue, and either omitting the primary antibody from the staining schedule or replacing the specific primary antibody by an immunoglobulin that is directed against an unrelated antigen.

Answer 2

Negative Control

Question 3

: Also named as “built in” control, this eliminates the variable of tissue fixation between specimens and controls but it contains the target antigen, not only in the tissue elements under investigation,

e.g. tumors, but also in adjacent normal tissue element. One example is the presence of S-100 protein in both melanoma and normal tissue elements, such as peripheral nerves and melanocytes.

Answer 3

Internal Tissue Control

Question 4

Chromogenic multi-immunohistochemical staining is based on immunoenzymatic reaction with_____ and______.

Chromogenic IHC staining can generate dense deposits that are easy to detect but difficult to quantitate, because of nonlinear optical effects and low achievable dynamic ranges.

Answer 4

chromogen and enzyme

Question 5

Chromogenic method

In facilitating chromogenic detection, the primary antibody, secondary antibody, or streptavidin is conjugated to an_____.

_________and________, which convert_____ and______, into brown and red end products, respectively are commonly used enzymes.

Answer 5

enzyme

Horseradish peroxidase (HRP); alkaline phosphatase

3,3’ diaminobenzidine (DAB); 3-amino-9-ethylcarbazole (AEC)

Question 6

is considered to be a more sensitive method than immunofluorescence. It requires only a typical light microscope unlike fluorescence microscopy which requires a specialized light source and filter sets.

Answer 6

Chromogenic detection

Question 7

An advantage of ______staining is that the colored precipitate formed during the reaction between HRP and DAB is not sensitive to light and the slides can be stored for many years.

Answer 7

DAB chromogenic