Examination of Blood

The various tests used for the examination of blood during forensic investigation.

1. GURU GHASIDAS VISHWAVIDHYALA BILASPUR, C.G. DEPARTMENT OF FORENSIC SCIENCE TOPIC :- COMPONENT AND EXAMINATION OF BLOOD SUBMITTED BY :- SUBMITTED TO:- PAHELI SHARMA Dr. I. ARJUN RAO 17205257 FORENSIC BIOLOGY ( B.Sc 5 th semester) AND SEROLOGY

2. CONTENTS INTRODUCTION COMPONENTS OF BLOOD EXAMINATION OF BLOOD PRELIMINARY TESTS OF BLOOD CONFIRMATORY TESTS OF BLOOD FORENSIC SIGNIFICANCE OF BLOOD REFERENCE

3. INTRODUCTION Blood is the most well known & significant evidence in modern criminal justice system. It has been always considered as a class evidence in criminal justice system. As every contact leaves a trace ( Locard’s Exchange principle )- given by Dr. Edmond Locard leaves the clue for forensic investigation.

4. COMPONENTS OF BLOOD Blood constitutes 8% of the human body weight . It is made up of fluid portion plasma( which constitute of 55% of total blood ) cellular parts,proteins , enzymes and inorganic substances.

5. ERYTHROCYTES/RBC - It contains red pigment called as Hb which is made up of Ferro- Protoporphyrin . These cells do not contain nucleus & donot contain genetic material. It helps in transportation of oxygen. LEUCOCYTES/WBC- It contains nucleus.It is subjected to most intense examination by forensic scientists because it helps in DNA analysis (individualization).It helps in defence mechanism. It is of 2 types: Granulocytes( Neutrophils , Eosinophils , Basophils ) and Agranulocytes (Lymphocytes , Monocytes ). THROMBOCYTES/PLATELETS- These are without nucleus and helps in blood clotting.

6. EXAMINATION OF BLOOD PRELIMINARY TEST- Kastlemeyer Test/ Phenopthaline Test Leuco Malachite Green (LMG) Test Tetra methyl Benzidine (TMB) Test Luminol Test Fluorescin Test CONFIRMATORY TEST- Takayama Test ( Haemochromagen crystal assay) Tiechmann’s Test ( Hematin crystal assay )

7. PRELIMINARY TESTS PRINCIPLE - These test is based on oxidation reduction reaction . Heme is utilized as a catalysts and hydrogen peroxide is utilized as an oxidising agent.In the presence of heme the colourless substrate is oxidized yielding a product with colour chemilumensence and fluorescence. KASTLEMEYER/PHENOPTHALINE TEST- ( Phenopthaline , KOH ,Zn dust ,distilled water , EtOH ,Hydrogen peroxide) Result- An intense pink colour indicates of hthe presence eme content. TMB TEST- Sodium acetate, ,glacial acetic acid, TMB reagent distilled water H2O2 Result – An immediate blue green colour indicates the presence of heme content.

8. LMG TEST – LMG reagent glacial acetic acid distilled water Zn dust 3% hydrogen peroxide. Result- An intense green colour shows the presence of heme content.

9. LUMINOL TEST- Sodium carbonate luminol powder distilled water hydrogen peroxide .(Best to identify latent bloodstains and footprints & fingerprints) Result- An immediate blue colour chemiluminescence shows the activity of heme content. FLUORESCEIN TEST- NaOH fluorescein hydrogen peroxide distilled water. Result- An immediate green colour fluorescence shows the presence of heme activity (important for latent prints and blood development).

10. CONFIRMATORY TESTS TAKAYAMA TEST- Standard glucose solution NaOH pyridine distilled water. Result- The appearance of pink needle shaped crystals of pyridine Ferro protoporphyrin is a positive reaction for heme & confirms the presence of blood. TIECHMANN’S TEST- KCl glacial acetic acid distilled water . Result- the appearance of brown rhombohedral crystals of ferro protoporphyrin chloride is a positive reaction for heme & confirms the presence of blood .(better for aged samples).

11. FORENSIC SIGNIFICANCE OF BLOOD It links a victim to a suspect via locard exchange principle. Blood stain pattern reveals about position and movement during crime. It destroys self defence arguments of suspect. Individualization of blood can be done blood typing and DNA profiling. Alcohol and drug content can be determined from wet blood. Freshness of blood can be detected by serum(it clots few minutes after exposure to air). DNA analysis has allowed forensic scientists to associate blood to single individual. Sex can be determined by identification of baar bodies(if present sex is female). BLOOD ANALYSIS NEEDS FOLLOWING QUESTIONS TO ANSWER:- Is the sample,blood ? Is the sample human blood or animal blood? If the blood is of human origin .How closely it is associated to particular individual?

12. REFERENCE- Richard Li (Forensic biology & serology) www.Slideshare.net THANK YOU