Differex™ System Technical Manual
Literature # TM331
The Differex™ System is an easy and efficient method to separate epithelial and sperm DNA and reduces variability in results from one examiner to another, a problem common to other differential extraction methods. In addition, through the use of the DNA IQ™ Resin to cap the pellet, fewer sperm are lost during the process. The proteinase K digestion from the standard methodology is retained for the upfront processing of the solid support. The Differex™ Magnet has two different positions because the position and shape of the pellet formed after each centrifugation step differs slightly. The DNA IQ™ Resin migrates to the magnet and caps the sperm pellet. The two separate magnets allow the DNA IQ™ Resin to form a better cap over the pellets.
The total time to separate sperm from epithelial cells after adding the sample to the proteinase K-containing Digestion Solution is approximately 2 hours, which includes a 90-minute proteinase K digestion. DNA purification requires 30 minutes, so separation and purification can be accomplished in as little as 2.5 hours.
Summary of Changes
The following changes were made to the 9/22 revision of this document:
1. Edited Step 4 in Section 3.C.
2. Updated document font.