It can be extremely difficult to obtain good yields of motile sperm from highly viscous semen samples.
Nidacon has developed a method that could be helpful to you in solving this problem in the lab. The method is very simple and convenient. You simply add Pure Sperm®Buffer to the ejaculate, incubate for short time and the sample is then ready for use.
When using PureSperm®Buffer, you will find a much higher proportion of motile sperm compared to before the incubation, due to reduced viscosity. The method has been tested at Cecolfes, Bogota, Colombia and their conclusion was:
Considerable diminishment of the viscosity in a lapse of 5-10 min. making it easier to handle the samples. After the dilution with PureSperm®Buffer, we recommend that you use a density gradient centrifugation to purify and separate the sperm.
Preparation of a viscous sample:
_ Measure the volume of the semen sample
_ Dilute 1:4 , 1 part PureSperm®Buffer and 3 parts sample (e.g. 0.5 ml PureSperm® Buffer + 1.5 ml semen sample)
_ Incubate at 37°C for 15-30 minutes
_ Mix using a pipette
_ Ready for sperm preparation using a density gradient