Effect of the MACS technique on rabbit sperm motility

Magnetic-activated cell sorting (MACS) separates apoptotic spermatozoa by the use of annexin V-conjugated nanoparticles which bind to phosphatidylserine that is externalized on the outer leaflet of the sperm plasma membrane. This technique yields two fractions: annexin V-negative (AnV(-)) and annexin V-positive (AnV(+)). The aim of the study was to evaluate the effect of MACS application on the motility parameters of rabbit spermatozoa. Rabbit semen samples collected separately from 4 bucks (I, II, III, and IV) were filtered and separated in a MACS system. The semen samples from a control (untreated) group, AnV(-) and AnV(+) fraction were evaluated using CASA system. The experiment was replicated 4 times for each buck. The AnV(+) sperm had significantly lower concentration than the AnV(-) fractions and the control samples (P < 0.05 for bucks I, II, III, but not IV). We observed that the proportion of apoptotic spermatozoa in the semen of NZW bucks is about 20%. There was no significant difference in the percentage of motile and progressively motile spermatozoa between the AnVfractions and control samples. In conclusion, the MACS technique has no harmful effect on the rabbit sperm concentration and motility.