CODIS (Combined DNA
Index System)
Microsatellite loci
The standard human DNA forensic testing set used
by the FBI and RCMP comprises 13
loci, each of which is located on a separate
chromosome. The observed range of variation at these
loci is sufficient that the probability of any two
individuals showing the same pattern at all 13 loci
is <1 / 1015, more than
five orders-of-magnitude less than current human
population of 6 x 109. Note
that the CODIS set does not include markers for
the X- and Y-chromosomes, which are
typed separately.