medicolegal aspects of blood and other stains

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Transcript medicolegal aspects of blood and other stains

Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
Blood
 Seminal fluid
 Vaginal discharge
 Saliva
 Faecal stain
 Urine

Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
-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
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
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
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
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
1.
BENZIDINE TEST
stain extract
benzidine ┼
in
glacial acetic acid
┼
Blue colour
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
10 vol
hydogen peroxide
2.
KASTLE MAYER TEST
- Phenolphthalein in alkaline medium
-
Pink colour
3.
ORTHOTOLIDINE TEST
-
(4% orthotolidine in ethyl alcohol)+ glacial
acetic acid + H2O2
Green colour
-
4.
5.
LEUCHOMALACHITE GREEN TEST
Bluish green colour
LUMINAL TEST
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
RBC’s- confirmatory
 Species
 Sex
 Disease

Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

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

Detects blood where RBC structure is lost
and hemoglobin has undergone
chemical composition
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU

-
-
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
- Barr bodies in > 3% of polymorphs
- Y chromosome is fluorescent to quinacrine
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
Blood grouping
• red cell antigen
•White cell antigen
•Se protein polymorphism
•Red cell enzyme polymorphism
Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
ABO system
 Rh system
 MNSs group system
 Lutheran
 Duffy
 Lewis
 Kidd

Dr. Shiuli, Forensic Medicine & Toxicology, KGMU
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, KGMU
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
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
> 250 proteins & enzymes found in red
cell
 Established value in paternity testing
• Phopho glucomutase
• Adenylate kinase

Dr. Shiuli, Forensic Medicine & Toxicology, KGMU