A sex test
is a test which is used to determine whether human male DNA is present
in a forensic sample. There are two types of sex tests:
Differential Sex Test
The differential sex test will provide
you with information regarding whether a biological sample is from
a male or a female. The differential sex test examines the amelogenin
locus. The amelogenin locus is present in the X-Chromosome as well
as the Y-Chromosome, but the version of amelogenin in the X-Chromosome
is slightly different in the X-Chromosome than in the Y-Chromosome,
thus allowing identification of whether a sample is male or female
(male is xy and female is xx).
This test can be used to determine whether
a stain (underwear stain, tissue, bed sheet) is contributed by more
than one person and whether the stain came from a man or a woman.
Male Confirmatory Test
The male confirmatory test is a Y-Chromosome
test and specifically detects the Y-Chromosome. The Y-Chromosome is
present only in males, so this test will provide definitive proof of
whether male specific DNA is present. This test is particularly useful
if you are trying to match a stain with a male individual/suspect.
Because the Y-Chromosome test will detect only male DNA, it doesn't
matter if female DNA is mixed in with the male sample, you will still
obtain a pure profile for the male portion.
Types of samples
which can be tested include but are not limited to:
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Underwear stains |
|
Stains on bed sheets |
|
Tissues |
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