Colorimetry

Abstract Colorimetry is based on the observation that molecules absorb light. The wavelengths and efficiency of absorption depend on both the structure of the molecule and its environment, making absorption of light a useful tool for characterizing both small molecules and macromolecules. Colorimetric methods utilize these light‐absorbing spectral properties to measure the presence, concentration, or enzymatic activity of substances. Colorimetric methods have clinical applications primarily for the quantitative analysis of biological substances and enzymes or drugs and their metabolites in specimens using either their known spectral characteristics or their reactivity with other substances having known spectral characteristics. Colorimetry is also one of the commonly used detection methods in the development of modern analytical technologies, such as enzymed‐linked immunosorbent assays (ELISA) and microarray assays, in biomedical sciences.