In several studies it has been shown that Percoll separation is more efficient than swim-up for selecting motile spermatozoa with good fertilization ability ( McClure et al., 1989 Englert et al., 1992 Ng et al., 1992). The most common methods used today are the swim-up and gradient separation techniques. the swim-up technique ( Lopata et al., 1976), discontinuous Percoll density gradient centrifugation ( Pertoft et al., 1977 Pertoft et al., 1978 Gorus and Pipeleers, 1981), glass wool filtration ( Perry et al., 1977 Paulson et al., 1979) and centrifugation through albumin gradients ( Ericsson, 1977 Koper et al., 1979). Several methods have been used to select motile spermatozoa prior to assisted fertilization, e.g.
![brown particles in sperm brown particles in sperm](https://www.cbaextract.com/wp-content/uploads/Walnut-seed-Extract.jpg)
IVF, Percoll, PureSperm ®, sperm morphology, swim-up Introduction PureSperm ® seems to be an acceptable alternative to Percoll but although the percentage of sperm recovery was higher after PureSperm ® we still recommend the swim-up technique to be the first choice, as a higher percentage of progressive motile spermatozoa is obtained without using other chemicals than IVF culture medium. No significant differences in IVF results regarding fertilization and pregnancy rates were found when PureSperm ® or the swim-up technique were used for the sperm preparation. All gradient preparations showed a significant decrease in the teratozoospermia index compared to the ejaculate ( P < 0.01). Normal sperm morphology increased from 8–17.2% after using Percoll and to 12.7% and 11.4% after using a four-layer and a two-layer PureSperm ® gradient respectively. When using a two-layer PureSperm ® gradient, motility was significantly decreased ( P < 0.05) compared to Percoll. No difference in sperm recovery or sperm motility was found when comparing the use of Percoll and the four-layer gradient of PureSperm ®. In-vitro fertilization (IVF) results after using PureSperm ® for the sperm preparation were also evaluated. Recovery of motile and morphologically normal spermatozoa after using a four-layer Percoll and a two- and four-layer PureSperm ® gradient respectively was recorded. Silane-coated silica particles (PureSperm ®) were evaluated as an alternative to Percoll for gradient separation of spermatozoa, for use in assisted reproduction.