Figure 1.

Sperm DNA fragmentation test using the Sperm Chromatin Dispersion (SCD) technique. When sperm classification is performed using the images provided by the SCD-Halosperm® method, normal sperm containing nonfragmented DNA are scored as the sperm population showing large or medium halos of dispersed chromatin surrounding a compact and well-defined core (a, green arrow). Spermatozoa either containing small halos or no halos, i.e., leaving only the chromatin core visible, are considered as those containing fragmented DNA (a and b, blue arrows). Spermatozoa exhibiting highly degraded chromatin are characterized by the presence of small nucleoids presenting nonuniform or faintly stained chromatin core in association with the absence of a halo of dispersed chromatin after direct staining (b, red arrows; c).