Luminol

Luminol is a chemical compound that emits blue light when oxidized. Its chemiluminescence is used to reveal trace blood and other substances that catalyze the reaction.

Chemiluminescence: Light produced by a chemical reaction rather than by heating a material. Luminol’s blue glow is a classic example of light generated directly by chemical reactions.
Bloodstain pattern analysis: The interpretation of bloodstain locations, shapes, and distributions to reconstruct events. Luminol can reveal faint stains whose positions may contribute to pattern analysis.
Kastle–Meyer test: A presumptive blood test in which phenolphthalin turns pink when oxidized in the presence of a catalyst. Unlike luminol’s glow, this test signals a possible blood reaction with a pink color.
Albrecht 1928 chemiluminescence: The reported discovery by H. O. Albrecht that oxidized luminol emits blue light in alkaline solution. This early demonstration established the reaction’s striking light emission.
Latent bloodstain: A bloodstain that is not readily visible under ordinary viewing conditions. Luminol can make faint or cleaned blood traces visible in darkness.
Luminol reaction: The oxidation of luminol that produces an excited aminophthalate ion and visible light. This reaction is the direct source of luminol’s forensic blue glow.
Forensic chemistry: The application of chemical analysis to questions involving law and criminal investigations. Luminol is a presumptive chemical test used in forensic investigations.
Hemastix: A reagent strip that detects peroxidase-like activity, commonly used to test urine for blood. It uses related heme-catalyzed chemistry but reports a color change on a strip.
Walter Specht: A German forensic scientist who investigated luminol as a reagent for detecting blood traces. His work helped establish luminol’s place in forensic blood detection.
DNA profiling: The analysis of variable DNA regions to distinguish individuals or assess biological relationships. Luminol searches can precede DNA testing, though sampling and interpretation need care.

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LuminescenceBroader topic: Its chemiluminescence enables sensitive detection of some oxidizing reactions.