paternity testing,Maternity testing forensic applications,DNA Fingerprinting,DNA Profiling, steps for DNA profiling.

2. Paternity Testing
Forensic Applications
Presented by: Mariam Kareem
Naiha Sharif
Professor Name: Mam Ayesha
Program: BS Zoology
Semester: 6th

3. Parental Paternity Test
• Chorionic villus sampling (CVS)
The CVS procedure is preformed during the 10th and
8th week of pregnancy.
• Amniocentesis
The amniocentesis is performed during 14th and 24th
week of pregnancy. Guided by ultrasound , OB-GYN will
use a long needle to collect Amnio fluid through the
abdomen.

4. Paternity Testing
• A paternity testing is currently the most accurate test for seeing if a man is the biological father
to a child.
• A paternity test might be performed to resolve legal issues such as child support, child custody
or inheritance , or simply for peace of mind of the family concerned.
• A paternity test is done through DNA profiling.
• DNA profiling is the comparing of people’s DNA profiles , a unique set of encrypted numbers in
someone’s DNA that can be used to identify a person.

5. Parental Paternity Testing
Parental DNA paternity testing produces conclusive results with
0% of probability of paternity if the alleged father is not
biologically related to the child or with greater than 99.9%
probability of paternity if the alleged father is the biologically
father of the tested child.

6. There are two equally accurate ways to test for paternity:
Blood tests:
The potential father and child give blood samples at a medical
office. The facility sends the samples to a lab for analysis.
Cheek swabs:
The potential father and child swab the inside of their cheeks for
buccal (cheek) cells. You mail the cotton swab applicators to a
designated lab. If swabbing takes place in a medical setting, the
office sends the samples to a lab.
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7. Maternity DNA Testing
DNA maternity testing determines the biologically mother child relationship.
Applications for DNA maternity testing
Immigration DNA test
Surrogacy
Adoption

8. DNA Profiling
● DNA paternity testing is the use of DNA profiles to determine
whether an individual is the biological parent of another
individual.
● DNA profiling (also called DNA fingerprinting) is the process of
determining an individual's DNA characteristics. DNA analysis
intended to identify a species, rather than an individual, is called DNA
barcoding.
● Discovered by Sir Alec Jeffreys in 1984.

9. Methods of DNA profiling
Mitochondrial
analysis
Y chromosomes
analysis
RFLP analysis
In RFLP analysis, a DNA sample is digested
into fragments by one or more restriction
enzymes, and the resulting restriction
fragments are then separated by gel
electrophoresis according to their size.
STR analysis
Short Tandem Repeat analysis is a common
molecular biology method used to compare
allele repeats at specific loci in DNA between
two or more samples
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3
2
4

10. Forensic DNA test
• Forensic DNA testing technology has been
applied to identify suspects and victims in
violent crimes and discover identities of
victims in natural disasters.
• By analyzing and comparing reference
samples and biological materials such as
blood, tissues and fingers nails left
behind at a crime scene.

11. DNA Fingerprinting
 The technique which is used to identify and analyze
the variation on the basis of variation and
polymorphism in DNA sequence is called as DNA
fingerprinting.
 The process of DNA fingerprinting was invented by
Alex Jeffreys in 1985.

12. Application of DNA fingerprinting
Used to identify crime suspect.
Paternity testing.
Used to find out evolutionary history of an organism

13. ● Blood
● Hair
● Saliva
● Semen
● Body tissue cells
Biologically samples used for DNA fingerprinting

14. Steps for DNA Fingerprinting
• Isolation of DNA
DNA must be recovered from cells or tissues. Only a
small amount of blood hair or skin is needed to isolate
DNA.
sample prep DNA Binding Wash DNA Elution

15. Digestion of DNA by Restriction Endonucleases
 The DNA is cut into fragment using restriction enzymes.
 Each restriction enzyme cut DNA at specific base sequence.
 Commonly used restriction enzymes are (hind 1 ,Alu 1).
 Reaction mixture is incubated overnight at 37.C.

16.  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.
 The shorter fragments of DNA move faster than the longer
fragments of DNA.
 DNA is separated on basis of size.
Gel electrophoresis

17. Gel electrophoresis

18. Transfer of DNA on NYLON
membrane
The DNA fragments are transfer to a Nylon sheet by
placing the sheet on the gel and soaking them
over night through a process southern blotting.
Nylon membrane
Agarose Gel
Vacuum blotter
Whatman paper
Porous mat

19. Probing
Adding radioactive and colored probes to the
nylon sheet which is complementary to the
target sequences.
Each probe only sticks to the one or two specific
places on the sheet.

20. Hybridization
• Labeled probe DNA should be hybridized with
complementary sequences located on nylon
membrane for detection of nucleotide sequence.
• Membrane is washed to remove non specific
binding and clearing of the background.

21. To detect the sequences in genome bound with the hybridized radioactive
probe on membrane.
Technique involves alignment of hybridized membrane with X-ray
film.
The X-ray film alter its development shows multiple no. of bands that looks like
bar codes and known as DNA fingerprints.
Autoradiography

23. Any Question?