observed at high magnification (≥8400×).
Spermatozoa were analyzed at greater
than or equal to 8400x magnification by inverted microscope equipped with DIC/Nomarski differential interference contrast optics. At least 200 motile spermatozoa per semen sample were evaluated and percentages of normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV/one or more vacuoles occupying>50% of the sperm nuclear area) were determined. A spermatozoon was classified as morphologically normal when it exhibited a normal nucleus (smooth, symmetric and oval nucleus, width 3.28+/-0.20 microm, length 4.75+/-0.20 microm/absence of vacuoles occupying>4% of nuclear area) as well as acrosome, post-acrosomal lamina, neck and tail, besides not presenting cytoplasm around the head. One examiner, blinded to subject identity, performed the entire study.
http://php.med.unsw.edu.au/embryology/index.php?title=File:Human-_vacuolated_spermatozoa.jpg