Magnetic-activated cell sorting is not completely effective at reducing sperm DNA fragmentation.

PURPOSE: To determine whether there is a homogeneous reduction of sperm DNA fragmentation (SDF) in sperm samples recovered from the MACS procedure, compared to spermatozoa in the initial ejaculate (NEAT) and those retained in the column.

METHODS: This study investigated the relative change in sperm DNA quality (SDF) of neat ejaculates (10 idiopathic infertile and 10 normozoospermic patients) to subpopulations of spermatozoa that had passed through the column (MACS-) and those retained (MACS+) by the annexin-V conjugated microbeads.

RESULTS: While the MACS protocol was capable of reducing the mean proportion of SDF (59.2%; P = 0.000) and sperm with highly degraded DNA (SDD; 65.7%, P = 0.000) in all patients, the reduction was not homogeneous across the patient cohort. A significant positive correlation (r = 0.772, P = 0.000) was apparent between the level of SDF in the NEAT ejaculate and the efficacy of SDF reduction observed in the MACS- fraction.

CONCLUSION: MACS is capable of reducing the proportion of SDF, especially spermatozoa with a highly degraded DNA molecule. However, this reduction did not preclude the presence of a small subpopulation of spermatozoa with damaged DNA in the MACS- fraction. The MACS protocol was two- to threefold more efficient when the SDF in NEAT ejaculate was equal to or greater than 30%. In 4 of 20 individuals, the level of SDF after MACS resulted in semen for ICSI with a higher or non-significant reduction when compared to SDF observed in the NEAT ejaculate.