I did a PSA
test, but the test line is just barely visible. Is
this a positive test?
According to the
literature, there is a 90%
probability this is a true positive test. However,
this is just academic and from a practical point of view,
the test result should be regarded as inconclusive.
This calls for further investigation, perhaps with a
different method of surveillance--for example, covert video.
In order to be certain that the stain contains semen, the
test line must be equal or greater in intensity to the
control line. This represents a 100% probability that
the stain in fact contains semen. Representative
results are shown below:
Weak PSA test
Strong PSA test
I did an AP
test which came out POSITIVE, but the subsequent PSA test
was NEGATIVE. Is
this a positive test?
This test is
presumptively positive for semen, but it doesn't prove
it's semen, since the PSA test was negative. Therefore
the test should be regarded as inconclusive. This test
result sometimes happens in cases where there is only a
trace of semen on the garment, and the AP test paper absorbs
it all, leaving nothing for the PSA strip to detect.
If you are suspicious that there is only a trace of semen
there, then do the PSA test first. Using a Q-tip will
allow an AP test to be performed after a PSA test.
Keep in mind the AP test may be NEGATIVE even though the PSA
test is strongly POSITIVE, because the PSA test is 1000x
more sensitive than AP. PSA is the definitive test for
semen, and the AP-PSA combination test is designed for
strong semen stains, where both tests will be strongly
How long can
semen in stains be detected?
For years, but
the long answer is: acid phosphatase
(AP) can be detected in semen which has been discharged up
to 17 hours after intercourse, and prostate specific antigen
(PSA) for up to 36 hours. Once semen has been
discharged, then its chemical components become stable for
years. The explanation for this is that both AP and
PSA are proteins, and must have a certain three-dimensional
configuration to work. The vagina presents a hostile
chemical environment however, and rapidly denatures seminal
proteins in a fashion similar to egg whites when they are
cooked. After discharge, the residual non-denatured
proteins are no longer exposed to a hostile environment, and
there is virtually no time limit for their detection.
PSA actually has been detected in semen stains over 30 years
old. Items tested more closely to the time of
suspected intercourse give a more strongly positive test.
What does the
shipping box look like?
discreet in a generic, nondescript container. The return
address likewise is nondescript. If we said more about
it, then everyone would know, wouldn't they? The charge will show
up on your credit card statement as "PAYPAL *PRIVAFONE."
How do I
You may order
online using our PayPal shopping cart, by phone, or by sending a check
to PrivaFone, Inc. using our contact information.
Institutional customers may send a purchase order by email
How fast will
it get here?
shipping is by Priority Mail® (2-3 business days).
U.S. customers may opt for Express Mail®, which
business days. International shipping is by Express
International (3-5 business days) or Global Express
(1-3 business days). Global Express Guaranteed®
is equivalent to FedEx,
but at half the price.
What if I
don't want my order shipped to my home?
may have their order sent to a FedEx Office and held for
pick-up. To exercise this option, choose Express as
your shipping option and input the address of the FedEx
office as the shipping address in the PayPal shopping cart.
Orders will be sent by FedEx 2nd Day Air, which often
arrives the next day. To find the location of the FedEx
Office nearest you,
click here, and check the box labeled "Hold at location"
on the right side of the screen.
How do I
become a Dealer?
Do you have
any new products on the horizon?
strips are moving into the manufacturing stage. They
will be offered as an alternative to AP. Although not
as sensitive as AP strips, zinc strips are more specific.
Plus, they have that cool yellow color with bright pink
spots upon exposure to semen:
translate the Instructions into another language?
available in English, Portuguese,
or Arabic. To
request another language, contact us.