User:Bondmannn/Colorimetry (chemical method)

Colorimetric assays use reagents that undergo a measurable color change in the presence of the analyte. They are widely used in biochemistry to test for the presence of enzymes, specific compounds, antibodies, hormones and many more analytes. For example,


 * para-Nitrophenylphosphate is converted into a yellow product by alkaline phosphatase enzyme.
 * Coomassie Blue once binding to proteins elicits a spectrum shift, allowing quantitative dosage. A similar colorimetric assay, the Bicinchoninic acid assay, uses a chemical reaction to determine protein concentration.
 * Enzyme linked immunoassays use enzyme-complexed-antibodies to detect antigens. Binding of the antibody is often inferred from the color change of reagents such as TMB.