Chromogen

Definition

A chromogen is a substance that can be converted into a colored compound, often used in immunoassays to indicate the presence of specific antigens or antibodies. In laboratory analysis, chromogens are key components for visualizing results in assays like EIAs and ELISAs.

5 Must Know Facts For Your Next Test

1. Chromogens are essential for producing visible signals in enzyme-linked immunosorbent assays (ELISAs).
2. The color change from chromogens is typically measured using a spectrophotometer.
3. Common enzymes linked with chromogens in EIAs include horseradish peroxidase (HRP) and alkaline phosphatase (AP).
4. The intensity of the color produced by a chromogen correlates with the concentration of the target molecule.
5. Chromogenic substrates must be carefully selected to ensure they produce a clear, measurable color change.

Review Questions

• What role do chromogens play in ELISAs?
• Name two enzymes commonly associated with chromogens in immunoassays.
• How is the intensity of the color produced by a chromogen related to the concentration of the target molecule?

Related terms

Enzyme-Linked Immunosorbent Assay (ELISA):

A common laboratory technique used to detect and quantify antigens or antibodies using enzyme-linked reactions.

Horseradish Peroxidase (HRP): An enzyme frequently used in conjunction with chromogens to produce a detectable signal in various assays.

Spectrophotometer: An instrument used to measure the amount of light absorbed by a sample, often utilized to quantify color changes produced by chromogens.