Page 62 - Clinical Biochemistry 08PB804

• Most of the microsatellites show a high degree of polymorphism, which can be evaluated
by PCR technique, and used in:
1) Criminal Investigations.
2) Forensic identification.
3) Parentage testing (Biological father testing).
What are microsatellites?
Non-coding DNA contains genetic markers important for human identification. Microsatellites
are di-, tri-, or tetra nucleotide tandem repeats in DNA sequences. The number of repeats is
variable in populations of DNA and within the alleles of an individual. The sequence below
has a 20 dinucleotide repeat (40bp) stretch of CA that is shown in bold.

Figure 29: microsatellites

CGTTCAATAAGCAAAAATCCATAGTTTTAGGAATGTGGGCT
GCTTGGTGTGATGTAGAAGGCGCCAATGCATCTCGACGTAT
GCGTATACGGGTTACCCCCTTTGCAATCAGTGCACACACAC
ACACACACACACACACACACACACACACACAGTGCCAAGCA
AAAATAACGCCAAGCAGAACGAAGACGTTCTCGAGAACACC
AGAAGTTCGTGCTGTCGGGGCATGCGGCGAGTAAAGGGGAT
Applications of DNA Fingerprinting
1) Identifying paternity or maternity
2) Identifying criminals or victims.
3) Personal identifier.
4) Determining guilt or innocence.
5) Evolutionary relationships between organisms
DNA Microarrays: the Basis of DNA microarrays