Tunel assay: establishing a sperm dna fragmentation cut-off value for Egyptian infertile men

Abstract

Male factor infertility is responsible for half of all infertility cases. Conventional semen analysis is inadequate to evaluate male fertility. Sperm DNA fragmentation (SDF) test can be done by: direct methods such as Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) and Comet assay, or indirect like Sperm Chromatin Structure Assay (SCSA) and Sperm Chromatin Dispersion (SCD). TUNEL assay measures both single- and double-strand breaks and is technically less demanding, while SCSA tests for the susceptibility for nuclear DNA denaturation and samples should be sent to the reference lab. Studies showed that a single cut-off value does not fit all.