A new technique for analysis of human sperm morphology in unstained cells from raw semen

Sperm morphology analysis is a fundamental component of semen analysis, but its real significance has been clouded by the plethora of techniques used for its evaluation. Most involve different fixation and staining procedures that induce artefacts. Herein we describe Trumorph (Proiser R+D, Paterna, Spain), a new method for sperm morphology analysis based on examination of wet preparations of spermatozoa immobilised, after a short 60°C shock, in narrow chambers and examined by negative phase contrast microscopy. A range of morphological forms was observed, similar to those found using conventional fixed and stained preparations, but other forms were also found, distinguishable only by the optics used. The ease of preparation makes the Trumorph a robust method applicable for the analysis of living unmodified spermatozoa in a range of situations. Subsequent studies on well-characterised samples are required to describe the morphology of spermatozoa with fertilising potential.