What is Test used to detect blood group of blood stain: March 2007 and explain in detail?
Ans. D: Absorption elution test The Takayama Test is based on the reaction of pyridine with hemoglobin to form hemochromogen crystals. Takayama is a crystal test used for the confirmation of the presence of blood on samples. Benzidine test used to confirm the presence of blood - has been discontinued because the reagent is carcinogenic. It has largely been replaced by the Kastle-Meyer test, using a solution of phenolphthalein which turns pink in contact with even small traces of blood. The test works by detecting the presence of the enzyme peroxides in the blood. However, as this substance is also present in other biological materials, the Kastle-Meyer test is regarded as a screening procedure. It is highly sensitive, and positive reaction is judged presumptive of blood, and fuher confirmatory tests are carried out. Once a stain has been confirmed as blood it has to be determined whether it is human or animal. The precipitin test is used for this purpose. The precipitin test is sensitive, and will work on small traces of blood. The test is also known as the Uhlenbuth test. Spectrophotometric analysis of bloodstains allows them to be aged within the range of one day to three weeks. The Luminol test - The Luminol reacts with the iron complex in the blood's hemoglobin to produce a self-luminescence. The bloodstains literally glow in the dark with a faint bluish light. The most widely used method for finding invisible blood Blood group are determined in blood stains by: Latte's crust method Absorption-elution method Absorption-inhibition method Latex method Enzymological methods