Figure 1

Frequency of DNA fragmentation in human ejaculated spermatozoa. The percentage of DNA fragmentation in the above groups was determined using the terminal deoxynucleotidyl transferase mediated dUTP-nick end labeling (TUNEL) assay with or without Hoechst 33258 DNA staining. The arithmetic means of each group were obtained by adding the group's means, when reported by the cited studies, and dividing the sum by the number of the cited studies that evaluated that group. The Standard Error of each group shown in the graph demonstrates the variability between the results of the different studies. All five studies evaluated normal donors [13, 81, 175, 181, 182]. Three of the studies also assessed a group of infertile patients [13, 175, 181], two evaluated varicocele patients [81, 182], one evaluated cryptorchidism patients and two assessed testicular cancer patients [13, 81].