Individuality of DNA denaturation patterns in human sperm as measured by the sperm chromatin structure assay

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

“…The inclusion of these parameters is based on the assumption that spermatozoa ''selected'' by the female reproductive tract and oocyte vestments in vivo are also genetically adequate (Yanagimachi et al, 1995). This theory is not proven and is called into question by the heterogeneous chromatin condensation of spermatozoa that penetrate cervical mucus (Freundl et al, 1981), the high rate of spontaneous abortion in the general population, and by the absence of clinically significant correlations between conventional semen parameters and the presence of DNA strand breaks (Sun et al, 1997) or the susceptibility of sperm nuclear DNA to denaturation (Evenson et al, 1991;Spano et al, 2000). Therefore, the fundamental definitions of sperm quality in andrology laboratories do not adequately assess the parameters required for optimum fertility success; namely, sperm DNA/chromatin integrity.…”

“…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.…”

Embryo development after intracytoplasmic sperm injection can be predicted by assessment of sperm nuclear chromatin

“…Some methods for detecting sperm nuclear DNA fragmentation have been reported, including toluidine blue staining [27], DNA breakage detection-fluorescence in situ hybridization [28], in situ nick translation assays [29], comet assays [30], TUNEL assays [31] and sperm chromatin structure assay (SCSA Ò ) [6]. SCSA Ò has been presented as a useful method for detecting sperm DNA fragmentation (DNA fragmentation index; DFI) by applying flow cytometry.…”

“…Cytograms (as in [15]) were obtained by plotting the fluorescence intensity of each cell. The cells outside of the main population (COMP, %) were utilized as an index of this study [6,15] (Fig. 1b, c).…”

“…Studies using acridine orange (AO) fluorescent dye have revealed that human fertility is influenced by structural nuclear proteins of the sperm head [5]. Initial studies have supported a role for chromatin alterations in unexplained infertility [6].…”