Measurement of sperm DNA fragmentation using bright-field microscopy: comparison between sperm chromatin dispersion test and terminal uridine nick-end labeling assay.
OBJECTIVE
To compare sperm chromatin dispersion (SCD) test with terminal deoxynucleotidyle transferase-mediated terminal uridine nick-end labeling (TUNEL) assay in assessing DNA fragmentation in human sperm through bright-field microscopy.


METHODS
Prospectively designed, side-by-side comparative study.


METHODS
Medical genetics laboratory in a provincial research institution.


METHODS
Sixty male patients presented for infertility evaluation and 30 fertile, volunteer sperm donors.


METHODS
Semen analysis, SCD test, and TUNEL assay on the same semen sample and on the same spermatozoa.


METHODS
Sperm DNA fragmentation, determined by SCD test score or TUNEL assay score.


RESULTS
Sperm chromatin dispersion test and TUNEL assay identified similar proportions of sperm cells with DNA fragmentation in the same semen samples. When the SCD test and TUNEL assay were performed simultaneously on the same spermatozoa, TUNEL-negative sperm showed a large halo, whereas TUNEL-positive sperm showed no halo after Diff-Quik staining. However, in some sperm cells, DNA damage was detected by the SCD test but not by the TUNEL assay.


CONCLUSIONS
Sperm chromatin dispersion test and TUNEL assay are both effective in detecting sperm DNA damage. Using bright-field microscopy, the SCD test appears to be more sensitive than the TUNEL assay.
Zhang
Li-hong
LH
Department of Reproductive Medicine, Shandong Research Institute for Family Planning, Jinan, China. lihong01118@126.com
Qiu
Yi
Y
Wang
Ke-hua
KH
Wang
Qiuju
Q
Tao
Guozhen
G
Wang
Lei-guang
LG
D000328:Adult; D048430:Cell Shape; D042002:Chromatin Assembly and Disassembly / Q000502:physiology; D053938:DNA Fragmentation; D005298:Fertility / Q000235:genetics / Q000502:physiology; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000379:methods*; D007248:Infertility, Male / Q000235:genetics / Q000378:metabolism; D008297:Male; D008853:Microscopy / Q000379:methods*; D055101:Semen Analysis / Q000379:methods; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure*