Concordance among sperm deoxyribonucleic acid integrity assays and semen parameters

The sperm chromatin structure assay and TUNEL assay are moderately correlated measures of sperm DNA integrity but often yield conflicting results. The DNA fragmentation index is well correlated with semen analysis parameters, whereas TUNEL is not.


Peter J. Stahl, M.D., Chava Cogan, B.S., Akanksha Mehta, M.D., Alex Bolyakov, M.C.Sc., Darius A. Paduch, M.D., Ph.D., Marc Goldstein, M.D.

Volume 104, Issue 1, Pages 56–61



To assess the concordance of sperm chromatin structure assay (SCSA) results, epifluorescence TUNEL assay results, and standard semen parameters.


Prospective, observational study.


Tertiary referral andrology clinic.


A total of 212 men evaluated for subfertility by a single physician.


Clinical history, physical examination, semen analysis, SCSA, and TUNEL assay.

Main Outcome Measure(s):

Spearman’s rank correlation coefficients (r) between SCSA DNA fragmentation index (DFI), percentage TUNEL-positive sperm, and semen analysis parameters.


There was a positive correlation between SCSA DFI and TUNEL (r = 0.31), but the strength of this correlation was weaker than has previously been reported. The discordance rate between SCSA and TUNEL in classifying patients as normal or abnormal was 86 of 212 (40.6%). The SCSA DFI was moderately negatively correlated with sperm concentration and motility. The TUNEL results were unrelated to standard semen parameters.


The SCSA DFI and percentage TUNEL-positive sperm are moderately correlated measures of sperm DNA integrity but yield different results in a large percentage of patients. The DFI is well-correlated with semen analysis parameters, whereas TUNEL is not. These data indicate that the SCSA and TUNEL assay measure different aspects of sperm DNA integrity and should not be used interchangeably.

Read the full text at: