Date of Award


Degree Type


Degree Name

Bachelor of Science Honours


Faculty of Computing, Health and Science

First Advisor

Dr Peter Roberts

Second Advisor

Dr Peter Burton


Semen cryopreservation has an important role in assisted reproductive technology however, the cooling, freezing and thawing processes often result in a significant loss of sperm motility, viability and nuclear integrity. The destructive effects of cryopreservation are significantly exacerbated in samples exhibiting low sperm number and poor morphological characteristics. Recent research into infertility has focused on the correlation between excessive oxidation and subfertility, in particular radical induced lipid peroxidation within the phospholipid bilayer of the spermatozoon plasma membrane and the promotion of cellular damage as a result of antioxidant insufficiency. The aim of this study was to evaluate the effect of vitamin E on the survival and integrity of sperm from oligozoospermic and teratozoospermic men following cryo preservation. Ejaculated semen samples from 43 men undergoing assessment for infertility were identified as normal (n=23) or abnormal (n=20) according to WHO standards. Each semen sample was divided into 3 aliquots: The first fraction remained untreated and the second and third fractions were treated with cryomedia containing either 100µM or 200µM of the vitamin E analogue Trolox (6-hydroxy-2,5,7,8-teramethylchroman-2-carboxylic acid) prior to freezing. Post-thaw analysis included sperm survival rate, vitality staining, and assessment of DNA fragmentation using the TUNEL assay. Motile sperm concentration and morphological normality was significantly higher in normozoospermic semen compared to the abnormal samples (P