Volume 23, Issue 3 (July 1978)
Chemiluminescence in the Visualization of Forensic Bloodstains
The peroxidase-like activity of hemoglobin forms the basis for those tests most commonly employed for the preliminary identification of blood: the benzidine, phenolphthalein, and luminol tests. Among these the luminol reagent is unique in that its reaction with blood results in the production of light rather than color. This distinction makes it use somewhat inconvenient because of the need for darkness when the test is performed but also gives it its unique value. Since the luminol is applied as a spray, large areas may be quickly screened for blood; furthermore, luminol is relatively nondestructive to the surroundings (it is noncorrosive and nonstaining) and to the blood (it does not prevent subsequent identification tests or ABO blood grouping analysis although it does interfere with electrophoretic analysis of those systems thus far tested, erythrocyte acid phosphatase and phosphoglucomutase). Although often used in this manner to locate unnoticed blood for collection and further testing, a large part of the luminol test's value comes from the observation of patterns of blood residue which it makes visible. Traditionally, the only means of recording this information has been through written description. Although luminol photography has been previously reported  most people still believe that successful photography of the luminol test is impossible or at least very difficult. Since the previous publication we have continued testing and refining the luminol test and its photography, and it is now used and photographed whenever a crime scene is investigated in which it might be of value.