DNA Fingerprinting Maryam Ahmed Khan February 14, 2001

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

Contents n Definitions n Methods n Technical issues n Further developments

Media Coverage

1. DNA Fingerprinting n 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. n 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.

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 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.

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

HUMAN GENOME GENOME

n Extraction of DNA n Restriction enzyme digestion n Gel electrophoresis n RFLP or PCR n Hybridization and autoradiography n Interpretation of data n Population genetics and frequency estimates 2. How is DNA Fingerprinting done?

ProcessingofDNAProcessingofDNA

SouthernblotSouthernblot

PCR

Allele-specific oligonucleotide dot blot analysis

A Restriction Fragment Length Polymorphism (RFLP)

A Variable Number of Tandem Repeat Polymorphism

Gene Chip Probe Arrays

DNA profiling in kinship analysis