Sperm preparation techniques for A.R.T.

Two routine preperation techniques are described:
- swim-up
- Discontinuous density gradients

Swim-up
Specific medium is gently layered over semen in a sterile conical-based centrifuge tube. The tube is inclined at an angle of 45" and incubated for 1 hour at 37 °C.
lt is then gently returned to the upright position and the upper layer removed. This upper layer of motile cells is then diluted with à large volume of medium, centrifuged at 500g for 5 minutes, and finally resuspended in 0.5 ml of culture medium for analysis and A.R.T. procedures.

	Before swim-up
	After swim-up

Discontinuous density gradients

This technique gives good results in many cases.
Alternative products (AP) replace Percoll*wich has been whithdrawn from use in human clinical applications

The technique uses alternative products in two layers :

lower layer : AP : 90 or 80 % conc.
intermediary layer : AP 40 or 45 % conc.
Upper layer : patient sperm
After centrifugation, Two upper layers are eliminated and
the pellet at the bottom of the AP 80-90 % is resuspended in specific medium.
After a short centrigugation the new pellet is resuspending in 0,5-1 ml. specific medium.
then, the sperm is analysed before use in A.R.T. procedures.

Sometimes, it is necessary adding a swim-up procedure for having a best sample.