Please cite this article in press as: Evenson, D.P., The Sperm Chromatin Structure Assay (SCSA ®)... more Please cite this article in press as: Evenson, D.P., The Sperm Chromatin Structure Assay (SCSA ®) and other sperm DNA fragmentation tests for evaluation of sperm nuclear DNA integrity as related to fertility. Anim. Reprod. Sci. (2016),
The integrity of mammalian sperm DNA is of prime importance for the paternal genetic contribution... more The integrity of mammalian sperm DNA is of prime importance for the paternal genetic contribution to normal offspring. Damaged DNA in the single sperm that fertilizes the female egg can have a dramatic negative impact on fetal development. This comprehensive and detailed unit presents a rapid, reliable, practical test for DNA integrity based on staining with acridine orange. SCSA data have been conclusively shown to predict sub/infertility. This assay is ideally suited to human and animal fertility clinics to assess male sperm DNA integrity as related to fertility potential and embryo development. The authors, who have decades of experience in studying sperm viability, provide extensive commentary and methodological tips, making this unit the most detailed method for this test published to date.
An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian s... more An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian sperm chromatin structural abnormalities, defined here as 'uncompensable', that lead to abnormalities in fertility, pronuclear formation, early embryo quality and pregnancy outcome. Sperm with uncompensable nuclear abnormalities are able to fertilize oocytes both in vivo and in vitro; however, due to the uncompensable trait(s), the embryo development may be abnormal. Uncompensable nuclear traits can be experimentally induced in bull sperm by a mild thermal insult to the testis. Sperm nuclear morphology abnormalities seen in ejaculates 11-days post stress are likely related to molecular changes in chromatin observed 3-days post stress by the flow cytometric sperm chromatin structure assay (SCSA). The SCSA measures the susceptibility of sperm nuclear DNA to denaturation in situ. This susceptibility has been correlated with the presence of DNA strand breaks that may be derived in part by oxidative stress and possibly by a unique, abortive apoptotic mechanism. The extent of DNA denaturation is not significantly related to the level of disulfide bonding between the chromatin protamines. The use of human sperm with uncompensable nuclear traits for artificial reproductive techniques is also discussed. The goal of this research is to remove from semen doses those sperm with uncompensable nuclear traits and thereby increase male fertility potential.
The reported effects on semen quality ascribed to tes- ticular heat stress generally relate to tr... more The reported effects on semen quality ascribed to tes- ticular heat stress generally relate to traits impacting sperm transport and fertilizing ability but not to the genetic material contained by the sperm. To characterize the effects of testicular heat stress on sperm chromatin, susceptibility of DNA in sperm nuclear chromatin to in situ acid denaturation was measured by flow cytometry
Data obtained by the sperm chromatin structure assay (SCSA) on spermatozoa from nine bulls were c... more Data obtained by the sperm chromatin structure assay (SCSA) on spermatozoa from nine bulls were correlated with fertility, measured by heterospermic performance (-0.94, P less than 0.01) and by alternate tests of sperm quality, including motility, acrosome integrity, Sephadex filtration and morphology of spermatozoa (all significant at P less than 0.05 to P less than 0.01). The SCSA uses flow cytometry to determine the susceptibility of nuclear DNA to low pH-induced denaturation in situ as measured by the ratio of acridine orange binding to double- or single-stranded DNA. The error associated with multiple SCSA measurements was relatively low. The primary finding is that the assay of chromatin structure stability performed on killed spermatozoa was as highly correlated with the heterospermic performance of semen as the best of the classical tests for semen quality. The SCSA may therefore be a highly useful technique for evaluation of sperm quality.
Methods in cell science : an official journal of the Society for In Vitro Biology, 2000
The Sperm Chromatin Structure Assay (SCSA) serves as a tool for measuring clinically important pr... more The Sperm Chromatin Structure Assay (SCSA) serves as a tool for measuring clinically important properties of sperm nuclear chromatin integrity. The assay utilizes the metachromatic features of Acridine Orange (AO), a DNA probe, and the principles of flow cytometry (FCM). SCSA data are not well correlated with classical sperm quality parameters and have been solidly shown to predict sub/infertility. This assay is ideally suited to human and animal fertility clinics to assess male sperm DNA integrity as related to fertility potential and embryo development as well as effects of reproductive toxicants. A detailed description of the SCSA follows.
Please cite this article in press as: Evenson, D.P., The Sperm Chromatin Structure Assay (SCSA ®)... more Please cite this article in press as: Evenson, D.P., The Sperm Chromatin Structure Assay (SCSA ®) and other sperm DNA fragmentation tests for evaluation of sperm nuclear DNA integrity as related to fertility. Anim. Reprod. Sci. (2016),
The integrity of mammalian sperm DNA is of prime importance for the paternal genetic contribution... more The integrity of mammalian sperm DNA is of prime importance for the paternal genetic contribution to normal offspring. Damaged DNA in the single sperm that fertilizes the female egg can have a dramatic negative impact on fetal development. This comprehensive and detailed unit presents a rapid, reliable, practical test for DNA integrity based on staining with acridine orange. SCSA data have been conclusively shown to predict sub/infertility. This assay is ideally suited to human and animal fertility clinics to assess male sperm DNA integrity as related to fertility potential and embryo development. The authors, who have decades of experience in studying sperm viability, provide extensive commentary and methodological tips, making this unit the most detailed method for this test published to date.
An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian s... more An important goal of modern analyses of semen is to elucidate the molecular traits of mammalian sperm chromatin structural abnormalities, defined here as 'uncompensable', that lead to abnormalities in fertility, pronuclear formation, early embryo quality and pregnancy outcome. Sperm with uncompensable nuclear abnormalities are able to fertilize oocytes both in vivo and in vitro; however, due to the uncompensable trait(s), the embryo development may be abnormal. Uncompensable nuclear traits can be experimentally induced in bull sperm by a mild thermal insult to the testis. Sperm nuclear morphology abnormalities seen in ejaculates 11-days post stress are likely related to molecular changes in chromatin observed 3-days post stress by the flow cytometric sperm chromatin structure assay (SCSA). The SCSA measures the susceptibility of sperm nuclear DNA to denaturation in situ. This susceptibility has been correlated with the presence of DNA strand breaks that may be derived in part by oxidative stress and possibly by a unique, abortive apoptotic mechanism. The extent of DNA denaturation is not significantly related to the level of disulfide bonding between the chromatin protamines. The use of human sperm with uncompensable nuclear traits for artificial reproductive techniques is also discussed. The goal of this research is to remove from semen doses those sperm with uncompensable nuclear traits and thereby increase male fertility potential.
The reported effects on semen quality ascribed to tes- ticular heat stress generally relate to tr... more The reported effects on semen quality ascribed to tes- ticular heat stress generally relate to traits impacting sperm transport and fertilizing ability but not to the genetic material contained by the sperm. To characterize the effects of testicular heat stress on sperm chromatin, susceptibility of DNA in sperm nuclear chromatin to in situ acid denaturation was measured by flow cytometry
Data obtained by the sperm chromatin structure assay (SCSA) on spermatozoa from nine bulls were c... more Data obtained by the sperm chromatin structure assay (SCSA) on spermatozoa from nine bulls were correlated with fertility, measured by heterospermic performance (-0.94, P less than 0.01) and by alternate tests of sperm quality, including motility, acrosome integrity, Sephadex filtration and morphology of spermatozoa (all significant at P less than 0.05 to P less than 0.01). The SCSA uses flow cytometry to determine the susceptibility of nuclear DNA to low pH-induced denaturation in situ as measured by the ratio of acridine orange binding to double- or single-stranded DNA. The error associated with multiple SCSA measurements was relatively low. The primary finding is that the assay of chromatin structure stability performed on killed spermatozoa was as highly correlated with the heterospermic performance of semen as the best of the classical tests for semen quality. The SCSA may therefore be a highly useful technique for evaluation of sperm quality.
Methods in cell science : an official journal of the Society for In Vitro Biology, 2000
The Sperm Chromatin Structure Assay (SCSA) serves as a tool for measuring clinically important pr... more The Sperm Chromatin Structure Assay (SCSA) serves as a tool for measuring clinically important properties of sperm nuclear chromatin integrity. The assay utilizes the metachromatic features of Acridine Orange (AO), a DNA probe, and the principles of flow cytometry (FCM). SCSA data are not well correlated with classical sperm quality parameters and have been solidly shown to predict sub/infertility. This assay is ideally suited to human and animal fertility clinics to assess male sperm DNA integrity as related to fertility potential and embryo development as well as effects of reproductive toxicants. A detailed description of the SCSA follows.
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