Evaluation of nuclear maturity in human spermatozoa obtained by sperm-preparation methods

Change in the nuclear maturity has been considered as an index of sperm quality. This is done by using aniline blue staining that stains spermatozoa with disturbances in the chromatin condensation. Therefore, this technique was used to evaluate the quality of sperm obtained by sperm preparation methods. In 14 semen samples from healthy donors with normal semen analysis and normal forms, the swim-up (SU), Percoll gradient centrifugation (PG), glass wool column filtration (GW) and sedimentation-migration (SM) were performed. GW and SM methods presented the lowest number of spermatozoa with alteration in the nuclear maturity (ANM), 11, 14% and 12, 42% compared to native semen (19%) (P < 0.005 and P < 0.05 respectively). SU and PG did presented no significant difference compared to native semen. In tests using the four methods, approximately 60% of the ANM occurred in normal spermatozoa. In the cells with pathologic abnormalities and ANM, 74.5% corresponded to macrocephalic forms, as this abnormality correlated mainly with ANM. It is concluded that in a semen sample with a higher percentage of normal forms, approximately 19% will have an ANM. GW and SM methods obtain the lowest percentage of ANM. ANM presents itself in 98% of the macrocephalic forms and they are effectively isolated with the PG method. The practice of this simple technique may orientate towards the sperm preparation methods to be used in assisted reproduction.