Trak Presents Sperm Motility Assay – 2018 ASRM Meeting

Development of an at-home sperm motility assay

We proudly revealed development of a Trak motile sperm count assay at the 2018 American Society for Reproductive Medicine (ASRM) meeting in Denver, Colorado.


Laura Fredriksen, Jon Epperson, Greg Sommer, and Ulrich Schaff


To determine if density-based motile sperm enrichment methods can be used for a motile sperm concentration assay upon the at-home centrifugal Trak® Male Fertility Testing System.


This study was conducted in two phases. First, the Trak total sperm concentration assay was empirically modified to selectively filter out non-motile cells. When assay methods were established, semen samples were then used to calibrate the motile cell pellet lengths for user readout.

Materials and Methods:

Assay development was an extension of the previously developed and 510(k) cleared Trak total sperm concentration assay, comprising a small battery-powered centrifuge (Engine) and a meso-fluidic disposable (Prop) that centrifugally packs sperm into a defined-volume channel containing a defined density medium for visual sperm concentration measurement. In this study the Trak assay was modified to isolate motile sperm from non-motile sperm by testing adjusted density medium formulations with both high-motile sperm samples and non-motile sperm samples to maximize high-motile concentration and minimize dead sperm pellet lengths. Additionally, the Engine spin rate was increased to further assist density separation of motile from non-motile cells. Using the optimal density medium, human semen samples were serially diluted and assayed on the device to calibrate the assay and determine tickmark locations for visual readout.


An optimal density medium was found by increasing the density of the total concentration medium and removing media components that may compromise sperm cell integrity, viability, or otherwise interfere with the motility assay function. Assay calibration was accomplished by serially diluting N= 10 unique semen samples provided by subjects. Pearson correlation coefficient of 0.93 was found and best-fit line calculated. Goodness of fit (r-squared) was found to be 0.87.


We successfully developed an at-home sperm motility assay that uses density-basedcentrifugal separation of motile from non-motile sperm cells – a standard laboratory sperm preparationtechnique. Because this new motility assay uses the same approach as the commercial Trak total sperm concentration assay, we expect it to be easy to use by lay users with no previous training in the comfort of home. Additional analytical performance and usability studies are forthcoming.

See Full Text at the Journal of Fertility and Sterility, September 2018, Volume 110, Issue 4, Supplement, Page e306