DNA MUGSHOTS AGAINST CRIME
Aug 23, 2014
DNA MUGSHOTS
AGAINST CRIME
SPECIES COUNT…….
About 8.7 million species is the new estimated count of species on Earth
All are different from each other
WHY IT IS SO?
DNA(deoxyribonucleic acid)DNA is often called
the blueprint of life. (source code of
organism)DNA contains the
instructions for making proteins within the cell.
3
Double Strand of DNADNA is polymer of
nucleotides
Pentose sugar + Nitrogen Base + Phosphate Group = Nucleotide
4 4
Nitrogenous basesBase pairs as ADENINE-
THYMINE double hydrogen
bond
GUANINE- CYTOSINE
Triple hydrogen bond
DNA USED IN….In forensic department- DNA Fingerprinting or other
Criminal investigationsDetermining whether a biological material is of human
originStudying the genetic ancestry of human ie.Family tree(solve Property Crimes)Genetic modification of organisms (plant ,animal and
bacteria) eg. Agriculture Healthcare (genetically engineered vaccines)Gene therapy Cloning
TECHNOLOGY AGAINST CRIMEEye-witness Sketch of criminalsFingerprints CCTV camerasNARCO testDNA-fingerprinting
DNA mugshots
How DNA is Used to Solve Crimes?DNA is uniqueinvestigators collect DNA samples from crime
scenes eg. few drops of blood, hair or dandruff , weapon,
sweat,etc.Get genome sequence or genetic codeIf samples doesn't match the victim then..compare it to samples from possible suspects If a suspect has left DNA at the crime scene, they
are definitely tied to the crime.
USING technique of DNA MUGSHOTS…
Currently we can't go from DNA to a face or from a face to DNA, but it may be possible.
New Computer Program Creates 3D ‘FACE image' From DNA
MUGSHOTS FROM DNA
• Using genes to predict eye and hair colour is relatively easy.
• But the complex structure of the face makes it more valuable as a forensic tool — and more difficult to connect to genetic variation.
• 7000 different components of face are compared by software and guessed which gene will impact where.
WORKFLOW:A) Original surface, B) Trim non-face parts, C) Reflect mirror image, D) Anthropometric mask of landmarks, E) Remapped, F) Reflected remap, G) Symmetrized, H) Reconstructed
DNA PROFILING
A technique used by scientists to distinguish between individuals of the same species using only samples of their DNA
Stages of DNA ProfilingStage 1: Cells are broken down to release DNA
If only a small amount of DNA is available it can be amplified using the polymerase chain reaction (PCR)
Stages of DNA Profiling Step 2: The DNA is cut into fragments using restriction
enzymes.
Each restriction enzyme cuts DNA at a specific base sequence.
Stages of DNA ProfilingThe sections of DNA that are cut out are
called restriction fragments.
This yields thousands of restriction fragments of all different sizes because the base sequences being cut may be far apart (long fragment) or close together (short fragment).
Stages of DNA ProfilingStage 3:Fragments are
separated on the basis of size using a process called gel electrophoresis.
DNA fragments are injected into wells and an electric current is applied along the gel.
Stages of DNA Profiling DNA is negatively
charged so it is attracted to the positive end of the gel.
The shorter DNA fragments move faster than the longer fragments.
DNA is separated on basis of size.
Stages of DNA ProfilingA radioactive
material is added which combines with the DNA fragments to produce a fluorescent image.
A photographic copy of the DNA bands is obtained.
Stages of DNA ProfilingStage 4:The pattern of fragment distribution is then
analysed.
Stages of DNA Profiling
Issues
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Based on case readings, doubts fall into the following themes:
(1) coincidental profile matches (2) unintentional attribution of DNA profile to
another(3) unfounded threats like planting of evidences and
eugenics (4) breadth of database.
Of these four, only the first can be deliberated within the world of “pure” science thereby crediting such doubts to DNA technology itself.
Issues
24
Coincidental Profile Match
In the cases reviewed for the past years , evidentiary samples from crime scenes are reported to be often incomplete or partial DNA profiles. Limited quantities of DNA can make it impossible to genotype at every locus (STR uses 13 loci as markers). In some instances, the test yields no information about the genotype at a particular locus; in some instances one of the two alleles at a locus will become undetectable.
Issues
25
Unintentional attribution of DNA profile to another
Unintentional attribution of DNA profile to another could be brought about by cross-contamination of samples, accidental transfer of DNA from one sample to another, mislabelling of samples, and misinterpretation of samples.
LimitationsDNA evidence is powerful, but it
does have limitations.•Fake DNA
Instances where criminals plant fake DNA samples at a crime scene
•High Tech lab
Skilled peoples Requiredplastic bags direct sunlight warmer conditions may damage DNA. so officers must be
skilled to handle biological materials.
AdvancementsNew testing procedures
RFLP( restriction fragment length polymorphism) analysis required large amounts of relatively high-quality DNA.
Newer procedures require far less DNA and can be completed faster.Source of DNA
Science has devised ingenious ways of extracting DNA from sources that used to be too difficult or too contaminated to use
Expanding DNA databaseThe databases managed by the CODIS
(Combined DNA Index System) software continue to expand.
Justice officials estimate the new collecting requirements will add DNA from an additional 1.2 million people to the database each year
Training To Investigators Crime labs have developed formal
protocols for handling and processing evidence, reducing the likelihood of contamination of samples
CONCLUSION
• DNA MUGSHOTS is the most sophisticated way to identify living organisms.•DNA cannot easily be altered once it is left at a crime scene which makes it a strong forensic tool.•laboratories carrying out DNA MUGSHOTS would perform the tests with the highest accuracy possible.