Fig. 1From: Analysis of human sperm DNA fragmentation index (DFI) related factors: a report of 1010 subfertile men in ChinaSperm DFI detected by flow cytometry. Sperm DFI was assessed by the sperm chromatin structure assay (SCSA). In brief, semen samples were treated for 30 s with 400 μl of a solution of 0.1 % Triton X-100, 0.15 mol/L NaCl, and 0.08 mol/L HCl, pH 1.2. After 30 s, 1.2 ml of staining buffer (6 μg/ml acridine orange [AO], 37 mmol/L citric acid, 126 mmol/L Na2HPO4, 1 mmol/L disodium EDTA, 0.15 mol/L NaCl, pH 6.0) was admixed to the test tube. The sample was placed into the FACS Calibur flow cytometer with the sample flowing to establish optimal sheath/sample flow, and then at exactly 3 min AO staining measurements were taken. A minimum of 5 000 cells from two aliquots of each sample were acquired and analyzed by FACS scan interfaced with a data analysis software. After completion of the sample analysis, the cytogram (red vs green fluorescence) and DFI readings were generated.Back to article page