2. A technique that detects mini-satellites
in the genome to produce a pattern
unique to an individual.
Also known as DNA profiling, DNA typing
and genetic fingerprinting.
WHAT IS DNA
FINGERPRINTING?
3. HISTORY
Science of fingerprinting was 1st
used by Sir William Herschel as a
method of identification in 1858
and in 1897 in India.
The DNA fingerprinting technique
was invented by Alec Jeffreys
(1984) at Leicester University,
United Kingdom.
4. PRINCIPLE
Human genome consists of non coding proteins
which make up 95% of DNA known as junk DNA.
They can be separated as satellites by density
centrifugation.
In satellites, repetition of bases is in tandem.
According to the length, base composition and
numbers of tandemly repetitive units, it is
divided as micro-satellites and mini-satellites.
At specific loci on the chromosome, the number
of tandem repeats varies between individuals.
5. APPLICATIONS
To study human lineage
To diagnose inherited
disorders
For forensic studies
To solve
paternity/maternity
disputes
6.
7. TECHNIQUE
1. Extraction of DNA
- from blood, saliva, semen, hair roots by salting
out proteins.
2. Digestion of DNA using restriction enzymes
- Restriction endonucleases recognize palindromic regions and cut DNA
forming sticky or blunt ends.
8. 3. Separation of the DNA fragments using gel electrophoresis
- occurs based on their size, shape, charge and
concentration of the agarose under the influence of an
electric field.
4. Transfer the DNA
- A nitrocellulose membrane or nylon sheet
is placed on the gel and allowed to soak
overnight by southern blotting.
9. 5. Probe labelling
- Complementary
radioactive probes are added
to the membrane and allowed
to hybridize. The excess
probes are washed off.
6. Autoradiography
- Exposed to X-ray film to
allow the variable fragments
to be visualized.
10. DISADVANTAGES
Collected evidence can be
stored indefinitely
Criminals are charged and
justice for victims
Measure individuality
Develop treatment for
inherited disorders
Not an obtrusive process
Infringement of privacy
Contamination can result
in false conclusions
False positive and false
negative results
ADVANTAGES
12. REFERENCES
Barh, D. and Azevedo, V. (2017) Omics Technologies and Bio-Engineering, pp. 591-625.
Bioscience Times (2018) DNA Fingerprinting- Principle, Methods, Applications [Online]. Available at:
https://www.biosciencetimes.com/molecular-biology/dna-fingerprinting/276/ (Accessed: 28 August
2019).
Kofanova, O. A., Mathieson, W., Thomas, G. A. and Betsou F. (2014) ‘DNA Fingerprinting: A Quality
Control Case Study for Human Biospecimen Authentication’, Biopreservation and Biobank, 12(2), pp.
151–153 [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3995361/ (Accessed:
27 August 2019).
Roewer, L., (2013) ‘DNA fingerprinting in forensics: past, present, future’, Investigative Genetics, 4(22)
[Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831584/ (Accessed: 28 August
2019).
Sciencing (2019) What are Specific Biotechnology Applications for DNA Fingerprinting? [Online].
Available at: https://sciencing.com/specific-biotechnology-applications-dna-fingerprinting-23975.html
(Accessed: 28 August 2019).
Your Article Library (2019) DNA Fingerprinting: Principles and Techniques of DNA Fingerprinting
[Online]. Available at: http://www.yourarticlelibrary.com/dna/dna-fingerprinting-principles-and-
techniques-of-dna-fingerprinting/12211 (Accessed: 28 August 2019).
Yourgenome.org. (2016) What is a DNA fingerprint? [Online] Available at:
This was discovered by chance during a murder investigation in Jalpaiguri.
A child receives 50% of the DNA from its father and the other 50% from his mother, so the number of VNTRs at a particular locus of the child will be different may be due to insertion, deletion or mutation in the base pairs. In which every individual has a distinct composition of VNTRs and this is the main principle of DNA fingerprinting.
