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Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University of Sciences and Technology (NUST)
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Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Dec 22, 2015

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Page 1: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Forensic Sciences and DNA Fingerprinting

LECTURE 22:

Biotechnology; 3 Credit hours

Atta-ur-Rahman School of Applied Biosciences (ASAB)

National University of Sciences and Technology (NUST)

Page 2: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Forensic Science

• Forensic biology is the application of biology to law enforcement

• The analysis of the biological or genetic properties of evidence for identification

• It is used to establish identity in criminal investigation, in case of disputed paternity, or in historical or archaeological research

Page 3: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

The Genetic Basis of Identity

1. Fingerprints2. Retinal Scan3. Blood Typing4. DNA Fingerprinting

Page 4: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

1- Fingerprints

• Finger prints are the classic example of a phenotype used in law enforcement

• They are due to the variation in the pattern of dermal ridges, small skin elevation on your fingers

Page 5: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Fingerprints

• Fingerprints pattern depends on more than one gene• They are multigenic• This create huge genetic diversity underlying this

phenotype • One could expect fingerprints of twins identical, but

they are not• Minor variation happens because of environmental

factors• This science is being used for identification by late

1800

Page 6: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

2- Retinal Scan

• Retinal scan provide a more high tech form of unique identification

• It take advantage of unique pattern of blood vessels on the retina on the back side of eye

Page 7: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Retinal Scan

• Scanning typically take about a minute• Several scans are required• Infrared light is used for this job, because blood

vessel on the retina absorb this better than the surrounding tissue

• A computer algorithm is used to convert this scan into digital data

• There are about 10 fold more information on retinal scan than in fingerprints

Page 8: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Applications

• Application in high security system• CIA, FBI, NASA and prison system• Now it is being employed on animal

identification• Fingerprinting in many security system and

also in law enforcement system (crime secene)

Page 9: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

3- Blood Typing

• Blood typing has been used in the courtroom for more than 50 years

• Other body fluids i.e. Sweat, tears, urine, saliva and semen also have cells with surface proteins that can be analyzed

• RBC contain many proteins and lipids for the identification

Page 10: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Blood Typing

• Galactose transferase• N-acetylgalactosamine

transferase

Page 11: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Blood Typing

Page 12: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Inheritance of ABO blood system

Page 13: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

4- What is a DNA fingerprint?

• DNA profiling (also called DNA testing, DNA typing, or genetic fingerprinting) is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles.

• DNA profiles are code sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier.

• It is used for parental testing and crime investigation.

Page 14: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

DNA fingerprint Profiling Analysis

a) RFLP Analysisb) PCR Analysisc) STR Analysisd) AmpFLP Analysise) Mitochondrial DNA Analysisf) Y-chromosome DNA Analysis

Page 15: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

a. RFLP Analysis

Page 16: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

b. PCR Analysis

Page 17: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

c. STR Analysis

Page 18: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

PCR Analysis

Page 19: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Paternity Testing

PCR amplification, then DNA fingerprinting

Page 20: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

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Offspring STRs

Mother’s STRs

STRs of suspected Father

Is the suspect the father?

Page 21: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

d. Genealogies by Mitochondrial & Y-chromosome DNA Analysis

• Genealogy is the study of families and the tracing of their lineages and history

• Mitochondrial DNA is maternally inherited and often used to specifically trace maternal ancestry

• Y chromosome can be used to trace male ancestry

Page 22: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

Genealogies by Mitochondrial & Y-chromosome DNA Analysis

• It is possible to submit personal samples of DNA for analysis to companies such as Oxford ancestor

• Their matri-Line service allows persons of European decedent to trace their maternal ancestry back to one of seven ancestral females

Page 23: Forensic Sciences and DNA Fingerprinting LECTURE 22: Biotechnology; 3 Credit hours Atta-ur-Rahman School of Applied Biosciences (ASAB) National University.

• Y-chromosome follows a paternal pattern of inheritance.

• The Y-chromosome contain many STR sequence in non-coding region.

• Y linked STR loci are specific to Y-chromosome• They find useful application in forensic

analysis in case of sexual assault.

Genealogies by Mitochondrial & Y-chromosome DNA Analysis