CODIS usats

CODIS (Combined DNA Index System) Microsatellite loci

The standard human DNA forensic testing set used by the FBI and RCMP comprises 13 microsatellite loci [boxes in grey and blue], all but two of which are located on separate chromosomes. The observed range of individual variation at these loci is great enough that the probability that any two individuals will have identical patterns at all 13 loci is <1 / 10¹⁵, more than five orders-of-magnitude lower than current human population of ~6 x 10⁹. Put another way, the probability that any individual and a forensic sample will be identical by chance is nil. The CODIS set does not include microsatellite loci on the X- and Y-chromosomes, which are typed simply by X- and Y-specific markers. Mitochondrial DNA (mtDNA) sequences in forensic applications are assessed by direct sequencing, and comparison with available databases.