Using a forensic kit, selected autosomal polymorphisms are amplified in a multiplex PCR. The polymorphic fragments of DNA are then separated in capillary electrophoresis. The same method is applied as well in forensic testing.
Why choose alternative dyes instead of "genuine" dyes? First, they are cheaper, and second, they can give the same results. Another reason is that the number of suppliers who can provide modified oligonucleotides is restricted - only a patent or a licence owner is usually allowed to produce them.