Researchers at Monash University in Australia have developed a microfluidic device to isolate high quality sperm from semen samples. The process could improve the chances of couples who opt for IVF to have children. The technology uses standing acoustic waves to separate sperm in clinically relevant numbers, and is faster, less labor-intensive, and not as damaging to sperm as current centrifugation and washing procedures. Approximately 1 in 6 couples can have trouble conceiving, with male infertility playing a role in about 30% of cases and a combination of male and female factors in roughly 50% of cases. For such couples, assisted reproduction, including In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI), may be an option. However, the procedures can be expensive and don’t always work, and if sperm quality is an issue then the chances of success are reduced. To address this, clinicians try to select the highest quality sperm from raw semen samples. “Male infertility is a global reproductive issue and several clinical approaches have been developed to tackle it,” said Reza Nosrati, a researcher involved in the study, in a press release. “However, their effectiveness is limited by the labor-intensive and time-consuming sperm selection procedures used.” Current approaches involve selecting sperm based primarily on motility, and haven’t changed much in 30 years. In fact, success rates have flat lined at approximately 33%, and there is a clear need for improvement. “Sperm preparation or selection is a key step in assisted reproduction being performed right before fertilizing the egg,” said Nosrati. “The current clinical process involves multiple washing and centrifugation steps and a manual selection step, and takes up to three hours to complete, which can also be harmful to sperm.” To address these issues, the Monash researchers have developed a microfluidic device that can rapidly and automatically isolate high-quality sperm from raw semen samples. The technique involves using acoustic waves to separate sperm with substantial DNA integrity and normal head morphology from the sample. “The approach isolates sperm from raw semen by applying an acoustic field at a 30° angle to the flow direction,” said Junyang Gai, another researcher involved in the study. “The acoustic forces direct and push high-quality sperm out of the mainstream, across the microchannel and isolates them in a separate outlet, leaving the general population of sperm in the raw sample.” The technique allows for the isolation of clinically relevant numbers of high-quality sperm, and the researchers hope that it could enhance outcomes for couples undergoing assisted reproduction. Source
