Dr Shiuli Forensic Medicine amp Toxicology KGMU Different stains having Medicolegal importance Blood Seminal fluid Vaginal discharge Saliva Faecal stain Urine Dr Shiuli Forensic Medicine amp Toxicology KGMU ID: 447908
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MEDICOLEGAL ASPECTS OF BLOOD AND OTHER STAINS
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide2
Different stains having
Medicolegal importance
Blood
Seminal fluid
Vaginal dischargeSalivaFaecal stainUrine
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide3
Blood stains
Main cellular content RBC –
Haemoglobin
which possess
peroxidase activityHaemoglobin and other proteins of blood has antigenic properties – produces antibodies when injected into animals
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide4
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 humanIn poisoning, poison chemically detectedTime since death may be estimated by chemical and enzymatic study
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide5
Examination
Whether the stain is actually a blood stain
Physical
Chemical
MicroscopicSpectroscopic
Micro chemical
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide6
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 deathWhether belong to victim or accusedWhether bleeding antemortem or postmortemAny disease process
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide7
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, KGMUSlide8
Mineral stains
Synthetic dye stains
Nitric acid
yellow
strong alkali
original color
Other stains
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide9
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, KGMUSlide10
BENZIDINE TEST
stain extract
┼
benzidine
┼
10
vol
in
hydogen
peroxide
glacial acetic acid
Blue
colour
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide11
KASTLE MAYER TEST
-
Phenolphthalein in alkaline medium
Pink
colour
ORTHOTOLIDINE TEST
(4%
orthotolidine
in ethyl alcohol)+ glacial acetic acid + H
2
O
2
Green
colour
LEUCHOMALACHITE GREEN TEST
Bluish green
colour
LUMINAL TEST
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide12
Confirmatory tests for blood
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide13
Microscopic test
RBC’s- confirmatory
Species
Sex
Disease Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide14
Microchemical test
HAEMIN CRYSTAL TEST/ TEICHMAN’S TEST
Sod. Chloride + strain extract + glacial acetic acid
Yellowish brown rhombic crystals
of haeminHAEMOCHROMOGEN CRYSTAL/ TAKAYAMA TEST
takayama
reagent + stain extract
Salmon pink
hemochromogen
crystals
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide15
Spectroscopic examination
Detects blood where RBC structure is lost and hemoglobin has undergone chemical composition
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide16
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, KGMUSlide17
Identifying sex from blood stain
- Barr bodies in > 3% of polymorphs
- Y chromosome is fluorescent to
quinacrine
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide18
Individuality by blood stain
Blood grouping
red cell antigen
White cell antigen
Se protein polymorphismRed cell enzyme polymorphism
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide19
Red cell antigen
ABO system
Rh
system
MNSs group systemLutheranDuffyLewisKidd
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide20
Group specific substances
secretors
Non secretors
Agglutinogens
in water soluble form
Secrete ABO antigens into body fluids and secretions
Agglutinogens
in
lipoidal
form
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide21
White cell antigen
Human
Leucocyte
Antigen (HLA)- the MHC in humans
Present on Chromosome 6 and encode cell surface antigen presenting proteins4 types – HLA-A, HLA-B, HLA-C, HLA-DDr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide22
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.
haptoglobinsSe lipoproteins
Abnormal
haemoglobins
Dr. Shiuli, Forensic Medicine & Toxicology, KGMUSlide23
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