title: Comparative evaluation of two density gradient preparations for sperm separation for medically assisted conception.
abstract: To evaluate and optimize the sperm separation efficiency of a novel silane-coated silica bead (Puresperm), serial studies were carried out to compare the various sperm parameters between: (i) three-layer (90%-70%-40%) Puresperm and three-layer (90%-70%-40%) conventional polyvinylpyrrolidone (PVP)-coated silica bead (Percoll) gradients; (ii) three-layer (90%-70%-40%) and two-layer (90%-45%) Puresperm gradients and separately the same for Percoll; and (iii) large (3.0 ml) and small (0.75 ml) semen loading volumes on three-layer Puresperm gradients. Normozoospermic semen samples were treated and analysed in 12 replicates for each experiment. Manual evaluation of concentration, percentage motility, percentage vitality, percentage normal morphology; computer-assisted semen analysis evaluation of concentration, percentage motility, grade of motility, motion characteristics (curvilinear velocity, linearity, amplitude of lateral head velocity, beat cross frequency, percentage hyperactivation); and yields from the initial semen samples were compared. Percoll was found to be superior to Puresperm in concentration, percentage motility, percentage vitality and yields after three-layer density gradient centrifugation. There were no significant differences in sperm parameters between two- and three-layer Percoll gradients, but three-layer Puresperm gradients behaved significantly better than two-layer gradients. Large semen volume loads on three-layer Puresperm gradients resulted in greater sperm concentrations, percentage motility, percentage vitality and percentage normal morphology, but small semen volume loads produced greater yields of good-quality spermatozoa. In the light of Percoll being withdrawn from the shelf for the use of assisted reproduction because of the presence of PVP, three-layer Puresperm gradients with large semen loading volumes appear to be an attractive alternative for sperm separation in medically assisted conception.
authors.affiliation: Department of Obstetrics and Gynaecology, National University Hospital, Singapore.
authors.forename: M J
authors.initials: MJ
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Bongso
mesh_terms: D000328:Adult; D002469:Cell Separation; D002499:Centrifugation, Density Gradient / Q000379:methods*; D006801:Humans; D008297:Male; D008863:Microspheres; D011205:Povidone; D012099:Reproductive Techniques; D012821:Silanes; D012822:Silicon Dioxide; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa
chemical_list: D012821:Silanes; C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone