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

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

3. 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

4. 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

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

6. 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

7. 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

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

9. 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

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

11. - 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

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

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

14. 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

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

16. 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

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

18. 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

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

20. 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

21. 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

22. 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

23. 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