The global population of infertility is about 15%
The global population of infertility is about 15%. Nowadays the in vitro fertilization (IVF) is the most efficient solution of infertility, while the pregnancy rate of IVF is only 37.4% is US. One of the reasons for the failure of IVF points to the inability to obtain healthy sperm. Spermatozoa used in IVF are obtained by gradient centrifugation method, it requires an operation time of 1 hour to increase twice the concentration of healthy sperm. The centrifugation is easy to