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Updated: May 6, 2026
Flow Cytometric Analysis of Biomarkers for Detecting Human Sperm Functional Defects
Published on: April 21, 2022
Diagnostic accuracy of sperm chromatin dispersion test to evaluate sperm deoxyribonucleic acid damage in men with
Cinthia M Feijó1, Sandro C Esteves1
1ANDROFERT, Andrology and Human Reproduction Clinic, Referral Center for Male Reproduction, Campinas, São Paulo, Brazil.
Objective:
To compare the sperm chromatin dispersion (SCD) test and the terminal uridine nick-end labeling (TUNEL) assay for assessment of sperm DNA damage.
Design:
Prospective comparative experimental study.
Setting:
Andrology laboratory.
Patient(S):
Twenty subfertile men with unexplained infertility.
Intervention(S):
Sperm DNA damage was determined in the same semen samples using the TUNEL assay with fluorescence microscopy and the SCD test with bright-field microscopy.
Main Outcome Measure(S):
Correlation coefficient and receiver operating characteristic analysis outcomes. The TUNEL assay was used as the reference standard to identify optimal cutoff points for assessing DNA damage by SCD.
Result(S):
The SCD test detected a significantly higher proportion of sperm with damaged DNA (20.6% ± 14.0%) than the TUNEL assay (11.5% ± 7.3%). Spearman's rank correlation showed that the methods were not comparable (r = 0.29). Receiver operating characteristic analysis revealed that 15% was the best SCD cutoff point to classify patients within the same levels of DNA fragmentation, normal or abnormal, as determined by the TUNEL assay, with an accuracy of 69%.
Conclusion(S):
The SCD test is more sensitive than the TUNEL assay for the assessment of DNA damage in men with unexplained infertility. Although the methods are poorly correlated, SCD may discriminate men with normal and abnormal sperm DNA damage with moderate accuracy when compared with TUNEL. It is important to distinguish between the methods because they differently evaluate sperm DNA damage.
Insights
The sperm chromatin dispersion (SCD) test is more sensitive but poorly correlated with the terminal uridine nick-end labeling (TUNEL) assay for sperm DNA damage assessment. SCD can moderately distinguish normal from abnormal DNA fragmentation compared to TUNEL.
Area of Science:
- Reproductive biology
- Andrology
- Sperm analysis
Background:
- Sperm DNA damage is a significant factor in male infertility.
- Accurate assessment of sperm DNA fragmentation is crucial for diagnosing and managing infertility.
Purpose of the Study:
- To compare the diagnostic accuracy of the sperm chromatin dispersion (SCD) test and the terminal uridine nick-end labeling (TUNEL) assay.
- To evaluate the correlation between SCD and TUNEL assays in assessing sperm DNA damage.
Main Methods:
- Prospective comparative experimental study involving 20 subfertile men.
- Sperm DNA damage assessed using both SCD and TUNEL assays on the same semen samples.
- Statistical analysis included correlation coefficients and receiver operating characteristic (ROC) analysis, with TUNEL as the reference standard.
Main Results:
- The SCD test identified a higher proportion of sperm DNA damage (20.6%) compared to the TUNEL assay (11.5%).
- Spearman's rank correlation showed poor comparability between the two methods (r = 0.29).
- An SCD cutoff of 15% achieved 69% accuracy in classifying DNA fragmentation levels consistent with the TUNEL assay.
Conclusions:
- The SCD test demonstrates higher sensitivity for detecting sperm DNA damage in men with unexplained infertility.
- Despite poor correlation, the SCD test can moderately discriminate between normal and abnormal sperm DNA damage levels when compared to the TUNEL assay.
- Understanding the differences in how SCD and TUNEL evaluate sperm DNA damage is essential for clinical interpretation.
