Thesis (MScMedSc (Obstetrics and Gynaecology))--University of Stellenbosch, 2005. / Chapter 1 contains a review dealing with nuclear and morphological changes during spermatogenesis and spermatozoa transport with emphasis on the maturation of spermatozoa, capacitation, acrosome reaction and the interaction with the cumulus oophorus complex (COC). The oocyte and cumulus oophorus complex is also discussed particularly on the topic of maturity (oocyte and cumulus maturity). Also presented is a review of the fluorescent binding agents, namely Fluorescein Isothiocyanate labeled with Pisum sativum (FITC-PSA), Chlorotetracycline test (CTC) and Chromomycin A3 (CMA3). Chapter II describes all the materials and methods used during this study. Routine semen analysis is described with emphasis on normal spermatozoon morphology according to strict criteria. The evaluation of capacitation and acrosome reaction (AR) using the CTC and PSA-FITC staining methods as well as the evaluation of spermatozoon nuclear chromatin packaging using the CMA3 staining method is described. Chapter III represents the results recorded in this study. Compared with those spermatozoa cultured in medium alone, spermatozoa exposed to the cumulus mass were more likely to be capacitated and acrosome reacted, with a distinct increase in chromatin packaging quality. A general discussion of the results and future applications are discussed in Chapter IV. In short An in vitro model for spermatozoa penetration through the cumulus oophorus was established. The model can be applied to investigate the effect of the cumulus oophorus on sperm functions and to assist in the selection of functional sperm for intracytoplasmic sperm injection therapy. All relevant references are presented in Chapter V .