The chemiluminescent compound luminol (so-called for its ability to emit light) is most commonly used in the field of forensic science for its capacity to react to previously invisible trace particles of blood. With a sensitivity of 1 particle in 5 million, it is of particular use where an environment is apparently ‘clean’, When applied in solution with dilute hydrogen peroxide the luminol will, if blood (specifically haemoglobin) is present, emit a brief though intense green / blue glow. [synonyms: 3-aminophthalhydrazide or 5-amino-2, 3-dihydro-1, 4-phthalazinedione]