DNA Fingerprinting

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DNA Fingerprinting
Maryam Ahmed Khan February 14, 2001
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Objectives

• What is DNA Fingerprinting?
• How is DNA Fingerprinting done?
• What are the applications of DNA Fingerprinting?
• Technical and legal issues.
• Further reading

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Contents

• Definitions
• Methods
• Technical issues
• Further developments

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Media Coverage
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1. DNA Fingerprinting

• The characterization of one or more features of
  an individual genome by developing a DNA fragment
  band (allele) pattern. If a sufficient number of
  different size bands are analysed the resultant
  bar code will be unique for each individual
  except identical twins.
• The term DNA fingerprinting was introduced by
  Alec Jeffreys in 1985, to describe the
  barcode-like DNA fragment pattern generated by
  probes after electrophoretic separation of
  genomic fragments.

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Definitions
Polymorphism One of two or more alternate forms
(alleles) of a chromosomal locus that differ in
nucleotide sequence or have variable numbers of
repeated nucleotide units. Polymerase chain
reaction a process which yields enzymatic
amplification of DNA in vitro. Primer starting
molecule that binds to single-stranded DNA or RNA
and facilitates synthesis of a complementary
strand. Satellite DNA repetitive DNA with
both repeat size and repeat copy number per locus
above 1000. Southern blot transfer of membrane
of DNA molecules separated by gel
electrophoresis. Molecular hybridization
formation of a DNA-DNA or DNA-RNA duplex in vitro.
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Abbreviations
RFLP Restriction Fragment length
polymorphism VNTR Variable number of tandem
repeats PCR Polymerase chain
reaction AMP-FLP Amplified fragment length
polymorphism STR Short tandem repeats
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HUMAN GENOME GENOME
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2. How is DNA Fingerprinting done?

• Extraction of DNA
• Restriction enzyme digestion
• Gel electrophoresis
• RFLP or PCR
• Hybridization and autoradiography
• Interpretation of data
• Population genetics and frequency estimates

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P r o c e s s i n g o f D N A
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S o u t h e r n b l o t
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PCR
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Allele-specific oligonucleotide dot blot analysis
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A Restriction Fragment Length Polymorphism (RFLP)
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A Variable Number of Tandem Repeat Polymorphism
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Gene Chip Probe Arrays
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DNA profiling in kinship analysis