Uploaded August 2026 | Updated September 2026, 3 weeks ago
A version of this video with audio description track is available here:
youtube.com/watch?v=naEwn4ybv60
Men with non-obstructive azoospermia may undergo microscopic testicular sperm extraction, or mTESE, without knowing whether sperm will be found. Kun Tan, Ph.D., of UC San Diego explains how molecular semen analysis could provide a noninvasive way to predict the procedure’s outcome. The assay uses stage-specific germ cell markers identified through single-cell RNA sequencing, then measures those markers in semen with qPCR. Because semen contains germ cells from different stages of sperm development, their molecular signals may reflect what is happening inside the testes. Tan shows how the assay predicts whether sperm retrieval was successful and can identify where sperm development may be blocked. The research could help couples planning IVF or ICSI avoid unnecessary surgery, reduce financial and emotional burdens, and receive more detailed information about male infertility before treatment. Recorded on 05/27/2026. [Show ID: 41630]
0:00 Male Infertility and the Limits of Sperm Retrieval Surgery
1:21 Why Testicular Biopsies Can Miss Sperm
2:09 Can Semen Reveal What Is Happening in the Testes?
2:36 Building a Molecular Semen Analysis
4:17 Predicting Sperm Retrieval Success Before Surgery
4:57 Identifying Where Sperm Development Stops
6:48 Expanding and Improving the Test
Donate to UCTV to support informative & inspiring programming:
uctv.tv/donate
Please Note: Knowledge about health and medicine is constantly evolving. This information may become out of date.
More videos from: UC San Diego Women's Health Symposium
(uctv.tv/ucsd-womens-health)
More from: Motherhood Channel
(uctv.tv/motherhood)
Explore More Health & Medicine on UCTV
(uctv.tv/health)
UCTV features the latest in health and medicine from University of California medical schools. Find the information you need on cancer, transplantation, obesity, disease and much more.
UCTV is the broadcast and online media platform of the University of California, featuring programming from its ten campuses, three national labs and affiliated research institutions. UCTV explores a broad spectrum of subjects for a general audience, including science, health and medicine, public affairs, humanities, arts and music, business, education, and agriculture. Launched in January 2000, UCTV embraces the core missions of the University of California -- teaching, research, and public service – by providing quality, in-depth television far beyond the campus borders to inquisitive viewers around the world.
(https://www.uctv.tv)
FAQ
Q: Can a semen test predict whether sperm will be found during mTESE?
A: Molecular semen analysis measures markers from different stages of sperm development. In the research presented, sperm-specific markers accurately predicted whether a previous mTESE procedure had successfully retrieved sperm.
Q: Why can a testicular biopsy fail to predict sperm retrieval?
A: Sperm production is not uniform throughout the testes. A biopsy taken from an area without active sperm development may not represent what is happening elsewhere in the tissue.
Q: How does molecular semen analysis work?
A: The assay uses qPCR to measure stage-specific germ cell markers in a semen sample. The pattern of those markers may show whether sperm are present and where the sperm development process has been disrupted.
A version of this video with audio description track is available here:
youtube.com/watch?v=naEwn4ybv60
Men with non-obstructive azoospermia may undergo microscopic testicular sperm extraction, or mTESE, without knowing whether sperm will be found. Kun Tan, Ph.D., of UC San Diego explains how molecular semen analysis could provide a noninvasive way to predict the procedure’s outcome. The assay uses stage-specific germ cell markers identified through single-cell RNA sequencing, then measures those markers in semen with qPCR. Because semen contains germ cells from different stages of sperm development, their molecular signals may reflect what is happening inside the testes. Tan shows how the assay predicts whether sperm retrieval was successful and can identify where sperm development may be blocked. The research could help couples planning IVF or ICSI avoid unnecessary surgery, reduce financial and emotional burdens, and receive more detailed information about male infertility before treatment. Recorded on 05/27/2026. [Show ID: 41630]
0:00 Male Infertility and the Limits of Sperm Retrieval Surgery
1:21 Why Testicular Biopsies Can Miss Sperm
2:09 Can Semen Reveal What Is Happening in the Testes?
2:36 Building a Molecular Semen Analysis
4:17 Predicting Sperm Retrieval Success Before Surgery
4:57 Identifying Where Sperm Development Stops
6:48 Expanding and Improving the Test
Donate to UCTV to support informative & inspiring programming:
uctv.tv/donate
Please Note: Knowledge about health and medicine is constantly evolving. This information may become out of date.
More videos from: UC San Diego Women's Health Symposium
(uctv.tv/ucsd-womens-health)
More from: Motherhood Channel
(uctv.tv/motherhood)
Explore More Health & Medicine on UCTV
(uctv.tv/health)
UCTV features the latest in health and medicine from University of California medical schools. Find the information you need on cancer, transplantation, obesity, disease and much more.
UCTV is the broadcast and online media platform of the University of California, featuring programming from its ten campuses, three national labs and affiliated research institutions. UCTV explores a broad spectrum of subjects for a general audience, including science, health and medicine, public affairs, humanities, arts and music, business, education, and agriculture. Launched in January 2000, UCTV embraces the core missions of the University of California -- teaching, research, and public service – by providing quality, in-depth television far beyond the campus borders to inquisitive viewers around the world.
(https://www.uctv.tv)
FAQ
Q: Can a semen test predict whether sperm will be found during mTESE?
A: Molecular semen analysis measures markers from different stages of sperm development. In the research presented, sperm-specific markers accurately predicted whether a previous mTESE procedure had successfully retrieved sperm.
Q: Why can a testicular biopsy fail to predict sperm retrieval?
A: Sperm production is not uniform throughout the testes. A biopsy taken from an area without active sperm development may not represent what is happening elsewhere in the tissue.
Q: How does molecular semen analysis work?
A: The assay uses qPCR to measure stage-specific germ cell markers in a semen sample. The pattern of those markers may show whether sperm are present and where the sperm development process has been disrupted.
