Sperm Chromatin Structure Assay: Its Clinical Use for Detecting Sperm DNA Fragmentation in Male Infertility and Comparisons With Other Techniques

Abstract

The Sperm Chromatin Structure Assay (SCSA) was first described in the December 5, 1980 issue of Science (Evenson et al, 1980a). The data described in that article showed a significant difference between proven fertile and subfertility or infertility in men and bulls and the susceptibility to denaturation of their sperm nuclear DNA. A subsequent study (Evenson et al, 1984) described SCSA data obtained from men with testicular cancer. The data were heterogeneous, and begged the question, what was SCSA measuring? Great effort has been spent over the past 15 years on animal model systems, mostly related to dose-response toxicology experiments and large animal fertility trials. The results from these studies showed that SCSA was highly dose-responsive to toxicants, highly repeatable, and provided meaningful biological information on sperm nuclear DNA defects. The extensive data from nonhumans (Evenson et al, 1985(Evenson et al, , 1989a(Evenson et al, ,b, 1993a(Evenson et al, ,b,c, 1994Ballachey et al, 1987Ballachey et al, , 1988Evenson and Jost, 1993; Sailer et al, 1995a,b;Evenson, 1999a), and human toxicology and fertility studies (Evenson et al, 1978(Evenson et al, , 1980a(Evenson et al, ,b, 1984(Evenson et al, , 1991Evenson and Melamed, 1983;Evenson, 1999b;Larson et al, 1999Larson et al, , 2000Larson et al, , 2001 provide This work was supported in part by grant R827019 from the US Environmental Protection Agency, grants EPS-9720642 and OSR-9452894 from the National Science Foundation, and by SCSA Diagnostics, Inc. This is South Dakota Agricultural Experiment Station publication 3273 of the journal series.Correspondence to: Donald P. Evenson, Olson Biochemistry Laboratories, ASC 136, South Dakota State University, Brookings, SD 57006 (e-mail: donald evenson@sdstate.edu).Received for publication September 20, 2001; accepted for publication September 20, 2001. compelling evidence that SCSA will be useful in clinical human semen analysis (Figure 1).After reviewing current infertility center sites on the World Wide Web and approximately a dozen lay-oriented books on infertility and assisted reproductive technology (ART), it was amazing that not a single reference contained any information about the negative influence of fragmented sperm nuclear DNA on successful pregnancy outcome. Furthermore, few physicians are aware of scientific literature on this subject. Currently, if a spermatozoon has some motility as seen under a light microscope, and reasonable morphology, then many ART clinics assume that the sperm DNA must be fine. However, a number of cases have been documented in which couples have had multiple failed attempts at intracytoplasmic sperm injection (ICSI), even using donor eggs, and we found that the fragmentation of sperm DNA was above our threshold for less than 1% probability of achieving a successful pregnancy. Spermatozoa with defective DNA can fertilize an oocyte, produce high-quality early stage embryos, and then, in relationship to the extent of DNA damage, fail in producing a successful term ...

Predictive value of DNA integrity analysis in idiopathic recurrent pregnancy loss following spontaneous conception

“…From large animal and human studies, Evenson and colleagues, who first described SCSA, suggested that threshold of 0-15 %. 16-29 % and >30 % DNA fragmentation index correlate to high, moderate and low fertility potential, respectively [16,18]. The clinical role of sperm DNA damage assessment by SCSA in assisted reproduction has also been established.…”

“…After complete analysis of the sample, the X-mean (red fluorescence) and Y-mean (green fluorescence) values were recorded manually after selecting gate for sperm cells using FlowJo software (Oregon). Extent of DNA denaturation (damage) was expressed as DFI, which is the ratio of red to total (red plus green) fluorescence, i.e., the level of denatured DNA over the total DNA [18]. The percentage of high DNA stainability cells (HDS) were also recorded in each sample manually from the graph plot.…”

Preparation and incubation conditions affect the DNA integrity of ejaculated human spermatozoa

“…Spermatozoa with increased levels of red fluorescence corresponding to increased levels of sperm DNA fragmentation were distributed outside the main population (green fluorescence; double-stranded DNA) and quantified on the basis of the percentage of spermatozoa with increased red fluorescence (%DFI). %HDS represents spermatozoa with incomplete chromatin condensation [9] and is expressed as the percentage of spermatozoa with high levels of green fluorescence (> 600 channels of fluorescence in this study, Figure 1). …”

“…754 npg Any failure(s) in this process during spermatogenesis may have a negative effect on male fertility as the highly organized and condensed sperm chromatin is known to have a crucial role in the normal fertilization process and embryo development [8][9][10].…”

Cytometric solutions in veterinary andrology: Developments, advantages, and limitations

“…However, it expresses different fluorescence properties depending on whether the DNA is single-or double-stranded: red in the former case and green in the latter (67,68). In some cases, the SCSA procedure is combined with counting cells and allows simultaneous determination of sperm numbers and concentration.…”