Proteomics is the analysis of the entire protein complement of a cell or organism under defined conditions. It relies on fractionating protein mixtures, mass spectrometry to identify proteins, and bioinformatics. Forensic science applies science to criminal law by analyzing scientific evidence. Proteomics can analyze proteins from samples like hair and teeth to deduce DNA sequences and identify individuals or determine their sex, even from degraded samples where DNA is limited. It has applications in human identification, species identification, and doping analysis from various tissues and biofluids.

1. PROTEOMICS IN
FORENSIC SCIENCES
P R E S E N T A T I O N B Y G R O U P V I

2. WHAT IS PROTEOMICS?
Proteomics is the analysis of the entire protein complement of a cell,
tissue, or organism under a specific, defined set of conditions.
In its present state, it is dependent on decades of technological and
instrumental developments. These developments have included advances
in mass spectrometry (MS) technology, protein fractionation techniques,
bioinformatics, etc.
Proteomics relies on three basic technological cornerstones that include
a method to fractionate complex protein or peptide mixtures, MS to
acquire the data necessary to identify individual proteins, and
bioinformatics to analyze and assemble the MS data.

4. WHAT IS FORENSIC SCIENCES?
Forensic science, also known as criminalistics, is the application of
science to criminal and civil laws, mainly—on the criminal side—during
criminal investigation, as governed by the legal standards of admissible
evidence and criminal procedure.
Forensic scientists collect, preserve, and analyze scientific evidence
during the course of an investigation..
Forensic science can be involved not only in investigation and
prosecution of crimes such as rape, murder, and drug trafficking but also
in matters in which a crime has not been committed but in which
is charged with a civil wrong , such as willful pollution of air or water or
causing industrial injuries.

6. PROTEOMICS AND FORENSIC
SCIENCES
DNA evidence has revolutionized forensic science in the past few
years, cracking open cold cases and bringing both convictions and
exonerations.
But DNA is a relatively fragile molecule that breaks down easily. That's
where proteomics, the new science of analyzing proteins, comes in. By
reading the sequence of amino acids from fragments of protein,
scientists can work backwards to infer the sequence of DNA that
produced the protein.
Proteomics technology could be used where samples are old or
degraded, and to back up results from DNA analysis.

7. Proteins are made up of chains of units called amino acids. There are
20 naturally occurring amino acids that are encoded by DNA.
A three-letter sequence of DNA corresponds to a specific amino acid,
so reading the sequence of DNA can give you the amino acid sequence
of the corresponding protein.
The DNA sequence can also be deduced by reading the amino acid
sequence and comparing it against databases of known proteins and
genes.
Some instruments can work with vanishingly small amounts of protein,
as little as 50 nanograms. An inch of human hair contains 100
micrograms of protein.

8. FORENSIC PROTEOMICS ON HAIR
Hair is often found at crime scenes. Hair has very little DNA, but more
than enough protein (mostly keratin) for analysis.
By looking at variant amino acids in keratin, researchers can identify
single-nucleotide polymorphisms, or SNPs, in the underlying DNA. That
information can be used for both personal identification and to get
information on ancestry.
Hairs vary somewhat depending on where on the body they come from,
that the differences between scalp, beard, armpit and pubic hair are not
great enough to affect identification.
Changes such as graying, dyeing and peroxide treatments had no effect
on the identifying information from peptides.

10. SEX DETERMINATION FROM TEETH
Teeth contain a protein called
amelogenin, which happens to be located
on the X and Y chromosomes that
determine biological sex.
If a tooth has amelogenin-Y, then it
must have come from an individual with
XY chromosomes and therefore most
likely a biological male.
In side-by-side tests, the tooth protein
analysis was more sensitive and reliable
for sex determination than either DNA or
looking at the anatomy of skeletons.

11. FINGERMARK PROTEOMICS
The chemical composition of fingermark
residue differs qualitatively and quantitatively
from the general chemical composition of sweat,
because it contains a complex mixture of
compounds coming from different glands and
not exclusively from the eccrine ones.
Chemical, physical and biological alterations
over time will also affect the fingermark residue
left on surfaces during a crime and hence modify
its initial composition.
The aging of fingermarks will then be
considered (aged composition), as well as the
variability of the composition due to influence
factors.

13. IDENTIFYING PEOPLE USING
PROTEINS FROM BONES
Now scientists have found a second way to use protein markers from
human tissue for identification—this time from bones.
Proteins are first extracted from a bone sample and broken down into
shorter amino acid chains, called peptides.
The researchers then use liquid chromatograph-mass spectrometry to
separate, detect and quantify the peptide sequences.
Results are compared to a protein sequence database to identify known
SAPs present in the sample.
Given data on the frequencies of each corresponding DNA mutation, the
researchers can derive identifying information and determine the
biogeographic origin of the person who provided a sample.

15. APPLICATIONS
Biofluid/tissue identification.
Human hair proteomics.
Bone.
Sports doping—targeted analysis of proteins and peptides in blood
and urine.
Species identification.
Taxonomic identification of microbes.

16. CONCLUSION
Proteomics methods have great potential in a wide variety of forensic
applications, some of which have been briefly considered here.
The strength of proteomics for forensic science lies in its selectivity, its
ability to complement genome sequencing and DNA techniques, and its
established procedures for considering error rates.
The outstanding issue of selecting the appropriate database is more
difficult and will require focused research efforts.
Finally, a fundamental statistical understanding of the occurrence of
incorrect peptide-spectrum matches is also an important research topic
that underpins all areas of proteomics, but has special resonance for
forensic science applications.

17. THANK YOU
PRESENTED BY
RAJ BAHADUR SINGH 18BSMBH005
KAMBHAM SAICHARAN REDDY18BSMBH011
PRIYA SINGH 18BSMBH029
HARSHIT SAURABH 18BSMBH048