Forensic Biology & Its biological significance.pdf

This Presentation provide all information about 'Forensic Biology and it's biological Significance '

Forensic Biology is the application of concepts and procedures used in the biological sciences, typically in a medico-legal context. Forensic biologists analyze cellular and tissue samples, as well as physiological fluids that are relevant to a legal investigation.

1. Rohan Singrore
B.Sc Forensic Science (2
nd
year)

2. Forensic Biology and It's
Forensic Significance
Submitted to: Neelanjana ma'am

3. Definition of
Forensic
Biology

4. Forensic Biology:-
Forensic Biology is that branch of forensic science which
involves application of knowledge of biological sciences in the
court of Law for the administration of Justice.
Forensic Biology mainly deals with the materials that are biological
in nature such as blood, hair, pollen etc found at the crime scenes
, with suspects and victims.

5. Forensic Biology:-
Forensic Biology involves the analysis of biological fluids
and tissues collected at crime scenes and from articles of
physical evidence for the purpose of identification and
individualization. A forensic biologist employs a wide
range of laboratory methods and instruments for body
fluid identification and forensic DNA analysis.

7. Importance of
Forensic
Biology:-

8. Importance of Forensic Biology:-
Forensic biology involves the application of biological principles and
techniques within the context of law enforcement
investigations.Forensic biology primary focuses on DNA sequencing
of biological matter discovered at crime scenes, aiding investigators
in identifying potential suspects or unidentified bodies.
This field encompasses various sub-branches, including as forensic
anthropology, forensic entomology, forensic odontology, forensic
pathology, and forensic toxicology.

9. Type's of
Evidence’s:-

10. Biological Evidence Type's:-
Biological evidence consists of bodily fluids and tissues. Biological evidence has
particular significance since DNA analysis can be conducted in many instances.
This DNA analysis may identify the donor. Examples of biological evidence
containing DNA include:
❏Blood.
❏Saliva.
❏Semen.
❏Sloughed skin cells.
❏Hair.
❏Urine.
❏Fecal material.

11. History and
development:-

12. History and development:-
The methods for producing a DNA
profile were developed by Alec Jeffreys
and his team in 1985. Jefferys discovered
that an unknown sample of DNA such as
blood, hair, saliva, or semen could be
analyzed and a unique DNA
pattern/profile could be developed.

Technologies:-
01.DNA analysis was first discovered, a
process called Restriction Fragment
Length Polymorphism (RFLP) was used
to analyze DNA.
02.Modern day technology has evolved
beyond RFLP. Short Tandem Repeat
(STR) analysis

13. DNA analysis
Techniques:-

14. DNA analysis Techniques:-
Types DNA Evidence Analysis
❏Polymerase Chain Reaction (PCR)
❏Short Tandem Repeats (STR)
❏Y-Chromosome
❏Mitochondrial DNA

15. DNA Typing — Short Tandem Repeat (STR) Analysis

Short tandem repeat (STR) technology is a forensic
analysis that evaluates specific regions (loci) that are
found on nuclear DNA. The variable (polymorphic)
nature of the STR regions that are analyzed for
forensic testing intensifies the discrimination
between one DNA profile and another.

16. DNA Typing — Polymerase Chain Reaction (PCR)
The evolution of DNA testing advanced significantly when Dr. Kary
Mullis discovered that DNA could be copied in the laboratory much as
it is in the natural world.
The copying process, known as polymerase chain reaction (PCR),
uses an enzyme (polymerase) to replicate DNA regions in a test tube.
By repeating the copying process, a small number of DNA molecules
can be reliably increased up to billions within several hours.

17. DNA Typing — Y-Chromosome Analysis
Several genetic markers have been identified on the Y
chromosome that can be used in forensic applications.
Y-chromosome markers target only the male fraction of a
biological sample. Therefore, this technique can be very
valuable if the laboratory detects complex mixtures (multiple
male contributors) within a biological evidence sample.

18. DNA Typing — Mitochondrial Analysis
Mitochondrial DNA (mtDNA) analysis allows forensic laboratories
to develop DNA profiles from evidence that may not be suitable for
RFLP or STR analysis. While RFLP and PCR techniques analyze
DNA extracted from the nucleus of a cell, mtDNA technology
analyzes DNA found in a different part of the cell, the
mitochondrion. Old remains and evidence lacking nucleated cells
— such as hair shafts, bones, and teeth — that are unamenable to
STR and RFLP testing may yield results if mtDNA analysis is
performed.

19. Composition of
Blood:-

20. Blood composition

21. Blood stain
analysis :-

22. Preliminary analysis of blood stain:-
Phenolphthalein Test( Also known as the Kastle Meyer Test):-A Phenolphthalein
solution is used to show the possible presence of blood based upon a peroxidase
reaction of hemoglobin which produces a pink color.
Luminol Test:-A chemical compound, known as Luminol, is used in solution or
sprayed onto suspected surfaces. This compound gives a strong blue
fluorescence when viewed with a UV light. The Luminol reacts with hematin, a
substanced formed as bloodstains age, and produces a luminescence which is
best observed in the dark.

23. Confrimatory analysis of blood stain:-
Takayama Test:-the application of a specific solution developed by
Takayama, hemochromogen crystals form by treating a small amount of
blood or a stain fragment. The crystals are observable under a microscope
and look like salmon-pink rhomboid crystals.
RSID Test for Human Blood:-This test uses two specialized antibodies to
detect the presence of human Glycophorin A which is found in red blood cell
membranes. The antibodies are applied to the suspected sample by using a
strip test assay. At the end of the test, certain markings will indicate whether
human blood was detected or if the test failed.

24. Seman analysis

25. Preliminary analysis of Seman
Acid Phosphatase Test(Also known as the Walker Test
or Brentamine spot test):-The male prostate gland
produces and secrets into semen a high amount of the
enzyme acid phosphatase (AP). In the presence of
Alpha-Naphthyl acid phosphate and Brentamine Fast
Blue, AP will produce a dark purple color in less than a
minute.

26. Confirmatory Analysis of Seman:-
Christmas Tree Stain:-Positive visual identification of sperm cells
using a stain. Two main reagents are used consecutively to produce
this distinctive stain: Picroindigocarmine stains the neck and tail
portions of the sperm in green and blue.
RSID Test for Semen:-Identifies the presence of the seminal
vesicle-specific antigen, or semonogelin. This antigen is unique to
human semen; therefore, there is no cross reactivity with other bodily
fluids in males and females or with semen from other mammals.

27. Saliva analysis:-

28. Preliminary & Confrimatory analysis of Saliva:-
Phadebas Test:-A chemical reagent called Phadebas is used to
detect the enzymatic activity of the alpha-amylase enzyme, which
is found in saliva.
Phadebas Test and RSID Test for Human Saliva:-The RSID Test
for Human Saliva detects the alpha-amylase molecule itself, and
specifically, the alpha-amylase from human saliva (in comparison
to the testing for enzymatic activity as seen in the Phadebas test).
Performing both of these tests is considered a confirmatory test.

29. Other Biological
Evidence's:-

30. Other Biological Evidence's:-
Biological evidence includes:
❖Urine
❖Tissues and cells
❖Bones and organs
❖Hair
❖Teeth
❖Fecal and fecal stains
❖Vomit
❖Stomach contents
❖Sweat
❖Ear wax

31. Biological
Analysis:-

32. Analysis of biological evidence:-
❏Toxicology:-Sample like blood, urine, vomits and stomach contents
are very useful in this analysis.
❏DNA Analysis:-DNA analysis is generally limited to things that are
biological in nature.
❏Histopathology Examination:-Tissue can serve as an important
sample especially for histopathology examination.
❏Anthropology:- define gender ,age, height of victim. Create different
between human & animal bone etc.

33. Case Studies:-

34. ➢Title: "Historic Breakthrough:
The Birth of DNA Profiling"
➢Subtitle: "Colin Pitchfork Case
Study"
➢Date: November 21, 1983 & July
31, 1986

35. Case's Study:-
Lynda Mann's Murder
➢Description of Lynda Mann's
disappearance on November 21, 1983
➢Discovery of her body on the "black
pad" footpath.
➢Initial forensic evidence: semen sample
with type A blood.
Dawn Ashworth's Murder
➢Description of Dawn Ashworth's
disappearance on July 31, 1986.
➢Discovery of her body near Ten
Pound Lane footpath.
➢Similarities to Lynda Mann's case:
modus operandi, semen sample with
type A blood.

36. Case's Study Theory:-
The world's first DNA-based manhunt took place between 1986 and 1988 in
Enderby, Leicestershire, UK, during the investigation of a double rape-murder:
Linda Mann (UK) in 1983, and Dawn Ashworth 1986. The prime suspect, a local boy
named Richard Buckland (UK), confessed to the second killing, but
Deoxyribonucleic acid (DNA) profiling of the victims revealed that the killer's DNA
and Buckland's DNA did not match. Buckland thus became the first suspect
cleared using DNA profiling. The actual killer, Colin Pitchfork (UK), who sent
another man's blood sample during the testing of 5,000 local men - was finally
caught after the falsehood was realised. Pitchfork's DNA matched that of the
killer and he was sentenced to life imprisonment in 1988

37. Future of
forensic biology
fields:-

38. Future of forensic biology fields:-
The recent technological and scientific development in the
field of forensic biology is certainly stamping a huge
impact in capturing and convicting the criminals without
any doubt. This review enlists forthcoming emerging
technologies in forensic biology which would become
inevitable and routine tasks in laboratories for solving
extremely challenging and critical cases.

39. Canclusion

40. Conclusion;-
forensic biology plays a crucial role in modern
criminal investigations, offering valuable insights
into the biological evidence found at crime scenes.
From DNA analysis to the identification of bodily
fluids and species, its significance in providing
concrete evidence for justice cannot be overstated.