FSC100H5 Lecture Notes - Lecture 14: Zygosity, Y Chromosome, Microsatellite
Document Summary
Dna recoverable from any cell with a nucleus. Red blood cells have no nuclei, no nuclear dna. No two individuals have same dna except for identical twins. Use probes tagged with fluorescent molecules to determine how much dna is present. In several areas of our dna there are regions with repeated sequences. When we look at several of these regions we can build a dna profile. Individuals have 2 copies (allelles) of each str. Both alleles have same number of repeats: homozygous. When a person cannot be excluded as the contributor of a dna profile it means: The person contributed the dna or the person is not the contributor and the coincidental match has occurred. Frequencies of different str alleles in different populations. Coi(cid:374)(cid:272)ide(cid:374)tal (cid:373)at(cid:272)h pro(cid:271)a(cid:271)ilit(cid:455) = str(cid:1005) (cid:454) str(cid:1006) (cid:454) str(cid:1007) (cid:454) str(cid:1005)(cid:1007) Perpetrators sperm mixed with the victims epithelial cells. Consider number of potential contributors, relative amount of dna. Targeting specific short tandem repeats (str) on y chromosome.
