Blood, avital biological uid, plays a nessential rolein sustaining life by transporting oxygen and nutrients, eliminating waste, regulating body temperature, and defending against infections. Blood, which is made up of red blood cells, white blood cells, platelets, and plasma, is extremely important for forensic purposes because of its DNA content and capacity to provide information about crimes. Blood at a crime scene can disclose information about the nature of the crime, identity of individuals involved, weapon used, and the sequence of events. Bloodstain patterns, trails, and smears assist in reconstructing the crime scene and determining positions and movements of both victim and perpetrator. In forensic science, blood detection begins with presumptive tests such as the Benzidine, Phenolphthalein (Kastle-Meyer), Leucomalachite Green, and Fluorescence tests. These rapid and sensitive methods rely on the peroxidase activity of hemoglobin to indicate possible blood presence, although they may yield false positives. The Teichmann and Takayama tests, which react with the heme components in blood togeneratecharacteristiccrystals, areusedas con rmatory tests toverify the existenceofblood.Advancedidenti cationmethodsincludeRamanspectroscopy, whichoffersmolecular-levelinsightsduetoitsnon-destructiveandhighlyspeci c nature. Immunoassays, including ELISA and RSID kits, detect blood through antibody-antigeninteractionsandare increasinglybeingadaptedfor elduse. Additionally, spectrographic techniques like FTIR and NIR hyperspectral imaging aid in blood stain detection and differentiation from other substances. While blood evidence may not always hold direct legal weight in court, it plays a crucial role in corroborating or challenging testimonies, establishing crime timelines, and linking suspectstocrimescenes. Itsscienti creliabilityandinterpretivepowermakeit a“silentwitness”thatsigni cantlycontributestocrimeinvestigationandjustice delivery.
Review Article
English
P. 32-39