New methods of semen analysis by CASA

Semen analysis constitutes the base for the establishment of fertility of a male. In addition, the number of insemination doses to produce from an ejaculate depends on the defined sperm characteristics. As soon as image analysis techniques were applied to biological problems the andrology was one of the first fields benefited both in the evaluation of genital track and sperm function. The improvement of image analysis expands possibilities of using developed systems in medical practice and animal husbandry. In ISAS®PBos («PROISER - Projectes i Serveis R+D S.L.», Spain) the semen analysis done includes concentration, motility and morphology. The systems with optimal rate of frame capture and transmission at images processing are developed for a two-dimensional analysis of spermatozoa motility in different species with regard to the spermatozoa sizes. ISAS®PBos calculates the percentage of morpho-abnormalities analysing the presence of cytoplasmic droplets and coiled tails base on the images used for motility analysis, and allows calculation of the optimal number of doses to produce from a particular ejaculate. Breed-dependent morphological diversity of spermatozoa found in different species, and a disclosure of structured subpolations of spermatozoa in the ejaculate, lead reproductive biology to the next level and open new prospects for the practice of animal breeding. In the study of spermatozoa at the subpopulation level the multivariate statistics which is based on an analysis of the principal components is applicable. In statistical estimation and mathematical modeling, it is proposed to use the Bayesian approach, on the basis of which a mathematical toolkit for estimating sperm quality will be developed in the near future. Essentially, the shortcomings of the early methods used for semen analysis are due to modifications of real motility of germ cells in counting chambers and the real shape and size of the spermatozoa under dehydration, fixation, staining and mounting. ISAS® 3DTrack and Trumorph® for estimation of sperm motility and morphology, respectively, avoid the limitations. ISAS® 3DTrack device, a lensless laser microscope, allows the analysis in a depth around 100 μm. Moreover, the analysis of the correspondent hologram allows the analysis of track in three dimensions what is also a big novelty. Trumorph® technique offers the maximum projection of the cells making it possible to obtain images of high resolution and definition of cells components in a wide range of species, including bull. ISAS® 3Fun with ISAS®3Fun kit and the correspondent software for automatic analysis is a new method enables a clear distinction of spermatozoa with intact plasmalemma and acrosome which are essential for sperm function.