MEDICOLEGAL ASPECTS OF BLOOD AND OTHER STAINS Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Different stains having Medicolegal importance Blood Seminal fluid Vaginal discharge Saliva Faecal stain Urine Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Blood stains Main cellular content RBC – Haemoglobin which possess peroxidase activity Haemoglobin and other proteins of blood has antigenic properties – produces antibodies when injected into animals Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Medicolegal importance May establish a link between offence, offended and offender May establish link between offence and offensive agent Fictitious charges by presenting an animal stain as human In poisoning, poison chemically detected Time since death may be estimated by chemical and enzymatic study Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Examination Whether the stain is actually a blood stain Physical Chemical Microscopic Spectroscopic Micro chemical Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Whether the blood stain is of human or other than human Precipitin test If human, which blood group Sex, source Indication as to cause of death Whether belong to victim or accused Whether bleeding antemortem or postmortem Any disease process Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Substances resembling blood stain Vegetable stains ammonia greenish yellow color Bleached by chlorine water M/E vegetable cells and fibers Rust stains Does not fall off in scale on being heated Positive reaction for iron Dissolved in dil. Hcl Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Mineral stains Synthetic dye stains Nitric acid yellow strong alkali original color Other stains Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Chemical examination Highly sensitive Positive reaction even with faint traces of blood Principal factor – peroxidase activity liberating nascent oxygen which leads to colour change Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

stain extract ┼ benzidine ┼ 10 vol BENZIDINE TEST stain extract ┼ benzidine ┼ 10 vol in hydogen peroxide glacial acetic acid Blue colour Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

- Phenolphthalein in alkaline medium ORTHOTOLIDINE TEST KASTLE MAYER TEST - Phenolphthalein in alkaline medium Pink colour ORTHOTOLIDINE TEST (4% orthotolidine in ethyl alcohol)+ glacial acetic acid + H2O2 Green colour LEUCHOMALACHITE GREEN TEST Bluish green colour LUMINAL TEST Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Confirmatory tests for blood Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Microscopic test RBC’s- confirmatory Species Sex Disease Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Microchemical test HAEMIN CRYSTAL TEST/ TEICHMAN’S TEST Sod. Chloride + strain extract + glacial acetic acid Yellowish brown rhombic crystals of haemin HAEMOCHROMOGEN CRYSTAL/ TAKAYAMA TEST takayama reagent + stain extract Salmon pink hemochromogen crystals Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Spectroscopic examination Detects blood where RBC structure is lost and hemoglobin has undergone chemical composition Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Species specification test PRECIPITIN TEST When human serum is injected in an experimental animal, antibodies develop. When any human serum is brought in contact with this animal serum, the antibodies and protein will react and a visible precipitate will develop Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Identifying sex from blood stain - Barr bodies in > 3% of polymorphs - Y chromosome is fluorescent to quinacrine Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Individuality by blood stain Blood grouping red cell antigen White cell antigen Se protein polymorphism Red cell enzyme polymorphism Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Red cell antigen ABO system Rh system MNSs group system Lutheran Duffy Lewis Kidd Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Group specific substances secretors Agglutinogens in water soluble form Secrete ABO antigens into body fluids and secretions Non secretors Agglutinogens in lipoidal form Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

White cell antigen Human Leucocyte Antigen (HLA)- the MHC in humans Present on Chromosome 6 and encode cell surface antigen presenting proteins 4 types – HLA-A, HLA-B, HLA-C, HLA-D Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Serum protein polymorphism Occurrence in the same population of two or more alleles at one locus, each with appreciable frequency, where the minimum frequency is taken as 1% Se. proteins subject to genetic variation are Se. haptoglobins Se lipoproteins Abnormal haemoglobins Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

Red cell enzyme polymorphism > 250 proteins & enzymes found in red cell Established value in paternity testing Phopho glucomutase Adenylate kinase Dr. Shiuli, Forensic Medicine & Toxicology, KGMU