IF YOU SUSPECT THE TESTED ITEM IS GOING TO YIELD A POSITIVE SEMEN DETECTION TEST RESULT BE SURE TO WEAR RUBBER GLOVES WHEN HANDLING THE GARMENT.

In many cases the types of samples we receive have often times been extensively handled by the submitters and many have come in contact with other items that have DNA on them. Examples are things like fingers, sheets, towels, other laundry items that can transfer DNA-containing epithelial cells from other people to the items submitted for testing.  As a result many items submitted can have very checkered histories if not handled properly prior to submission. Therefore if you're thinking about having DNA testing performed afterwards be sure to wear rubber gloves when handling the suspected item of clothing.

IMPORTANT FACTORS ABOUT DNA TESTING THAT MEN SHOULD CONSIDER

Isolation of total DNA collects DNA from sperm cells, cells shed in the seminal fluid from the prostate and urethra, as well as cells transferred by contact with other items.  Another problem with privately-submitted samples is that sometimes there are discrepancies regarding the conditions under which the items were collected or stored prior to submission.

Laboratories have the option to test for total DNA, which may actually provide too much information that can be misinterpreted resulting from the detection of DNA from contact sources or a utilize a more specific technique known as "differential lysis".  Many laboratories opt to utilize differential lysis which separates sperm cells from all other cells (epithelial cells from all sources, including contact sources).  The sperm cells are desorbed and collected, the DNA extracted then analyzed.  This approach ensures that the DNA profiles are from the intended source and produce a more specific, reliable result.  When abundant sperm cells are present DNA profiling is robust and very reliable.  Extraneous DNA profiles from incidental contact DNA can be easily eliminated from consideration as a primary source of DNA, even with isolation of total DNA.

Sperm cells lose their tails in a few days and if conditions are sub-optimal, they may even burst and release their DNA, leaving no intact sperm heads.  This occurs over time anyway.  Moisture encourages microbial growth and bacteria can degrade DNA rapidly which can compromise results even if abundant sperm WERE present.

THE CHECKMATE TEST WILL DETECT SEMEN FROM MEN WHO HAVE HAD A VASECTOMY PERFORMED

Vasectomized and sterile (aspermic) men do not have sperm; however, cells sloughed off in the genito-urinary tract often provide enough epithelial cells to detect DNA. While we can analyze DNA from vasectomized men using a total DNA isolation technique, those results may also contain genetic information from various other contact sources. For example, we often detect the submitter's DNA in profiles generated using the total DNA technique that was likely deposited from handling the area tested even though they were not involved as a sexual partner for weeks prior to collecting the sample submitted for testing and we suggest users of the CheckMate kit wear rubber gloves to prevent this from happening.

Since both the aspermic donor and any extraneous contact DNA may be present in similar amounts, interpretation with regard to "context" of how and why the particular DNA profiles were deposited on the suspicious item may be questionable if the suspected item was not handled properly prior to submission. In these cases the results should be interpreted with great caution because the results are often the basis for life-changing decisions. Our laboratory prefers to reject samples containing samples from known vasectomized or otherwise aspermic men so the results will be consistent and reliable rather than report a result that might be interpreted out of context.  We realize that not all vasectomized men will be known beforehand and we will consult with the client if we suspect this is the case so the results will be interpreted with appropriate caution on a case by case basis.