Scientists have discovered a novel way of separating strong sperm cells from their impotent peers.
By using an ingenious microchip method, researchers at Florida Atlantic University College of Engineering and Computer Science have developed a microfluidic chip for sperm sorting.
The chip is fast, inexpensive, easy to operate and efficiently isolates healthy sperm directly from semen, claim the researchers. The technique also reduces contamination by deformed or dead sperm cells.
Results of the study, published in Royal Society of Chemistry journal Analyst, showed that sperm cells isolated via microfluidic chip showed almost 100 per cent motility (the ability of sperm to swim the right way), higher morphologically normal cells and substantially lower DNA fragmentation. All three conditions are crucial in the fertilisation process.
The female genital tract can be a hostile environment for conception. Out of about 100 million sperm, only a few hundred make it to the fallopian tubes. Guided by a directional movement called rheotaxis, sperm cells swim against the cervical mucus flow to reach the egg for fertilisation.
The process involves a raw semen sample added to a sample inlet chamber. Functional sperm cells then swim towards a collecting chamber, separating themselves from dead and immotile sperm.
In the US, an estimated 15 per cent of couples have trouble conceiving. Globally, approximately 48.5 million couples experience infertility. According to the U.S. Centers for Disease Control and Prevention, 12 percent of women of childbearing age have used an infertility service.
And treatment does not come cheap: Infertility services in the United States can range from US$5,000 to US$73,000, with the average patient enduring two invitro fertilisation cycles. The cost of this procedure, plus medications, can easily reach $60,000.
Current centrifuge-based methods for sperm sorting require multiple steps, different types of equipment and take about two hours to isolate sperm cells. These methods damage sperm during processing and induce significant DNA fragmentation and oxidative stress.
The study bolsters earlier findings that rheotaxis selects healthy, motile, and higher velocity sperm cells for the fertilisation process.
Waseem Asghar, Ph.D., senior author, an associate professor in FAU’s Department of Electrical Engineering and Computer Science, claims the operating chip is simple to use, takes just an hour to perform its sperm selection task and requires little training.
The chip has commercial appeal too, costing less than US$5, including reagents.
