Chromogenic substrate

Definition

A chromogenic substrate is a molecule that releases a colored product when acted upon by an enzyme. It is often used in assays to detect enzyme activity and visualize antigen-antibody complexes.

5 Must Know Facts For Your Next Test

1. The color change from a chromogenic substrate indicates the presence of an enzyme linked to an antibody or antigen.
2. Chromogenic substrates are commonly used in ELISA (Enzyme-Linked Immunosorbent Assay) tests.
3. The intensity of the color produced can be measured quantitatively using spectrophotometry.
4. Common chromogenic substrates include p-nitrophenyl phosphate (PNPP) for alkaline phosphatase and 3,3',5,5'-Tetramethylbenzidine (TMB) for horseradish peroxidase.
5. The use of chromogenic substrates allows for the visualization and quantification of antigen-antibody interactions.

Related terms

ELISA:

A laboratory technique to detect antibodies or antigens in a sample using enzyme-linked immunosorbent assay.

Enzyme Substrate: A molecule upon which an enzyme acts to produce a product.

Antigen-Antibody Complex:

A complex formed when an antibody binds to its specific antigen.