Immunohistochemistry Flashcards
What is immunohistochemistry?
The analysis of cell components in tissue sections using antibodies
What is an antibody?
Immunoglobulin produced by B lymphocytes in response to the presentation of foreign proteins and microorganisms
What does an antibody bind to?
An epitope on an antigen
What does a polyclonal antibody represent?
A collection of antibodies from different B cells that recognise multiple epitopes on the same antigen
What does a monoclonal antibody represent?
Antibodies from a single antibody producing B cell that they therefore only bind with one unique epitope
Why do we need antigen retrieval?
Because there may be cross-links in place which mask the epitopes
What is HIER and what does it do?
Heat induced epitope retrieval - a type of antigen retrieval
Uses heat with specific buffered solutions to recover antigen from fixed tissue
What is PIER and what does it do?
Proteolytic induced epitope retrieval
Proteolytic enzymes selectively break protein links/bonds to reveal hidden epitopes
What is peroxidase?
An enzyme that catalyses the oxidation of substrate by hydrogen peroxide
What is chromogen?
A coloured chemical ‘end product’ used to visualise the localisation of an antibody/antigen reaction using light microscopy
Is chromogen soluble or insoluble?
Insoluble - we need it to not wash away
How many antigen binding sites do IgG antibodies have?
2
Which step is included to prevent non-specific binding?
Blocking
What is used to neutralise peroxidase found in tissues?
Endogenous enzyme inhibition
What is used to enable visualisation?
Chromogen
