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PCR A license to do molecular biology. DNA FINGERPRINTING BY PCR. POLYMORPHIC DNA. Chromosomal regions that vary widely from individual to individual
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PCR A license to do molecular biology
POLYMORPHIC DNA • Chromosomal regions that vary widely from individual to individual • By examining several of these polymorphic regions within the DNA, one may obtain a “DNA fingerprint”
Can identify criminals • Can determine paternity • Can identify human remains • Serve as markers for certaindiseases
Most commonly used polymorphisms are those which vary in length • FLPS-fragment length polymorphism • When amplified by PCR referred to as AmpliFLPs
VNTR • Variable number of tandem repeats • FLPs that contain specific sequences duplicated a variable # of times
D1S80 • Is a specific type of VNTR • Located on chromosome 1 • Contains a 16 nucleotide sequence • Variable repeated 16-40 times • D1S80 locus is one VNTR used by FBI
An individual who is homozygous For the D1S80 genotype will have equal repeat numbers on both homologues of chromosome 1 Yields a single PCR product seen on gel An individual who is heterozygous for the D1S80 genotype will have different D1S80 repeat numbers Yields 2 distinct PCR products seen on gel