PICSI is a method of selecting the best possible sperm for fertilisation in the IVF protocol. Sperms are placed in the PICSI dish containing samples of hyaluronan (a naturally occurring bopolymer found in all human cells) hydrogel.
What PICSI does is select sperm according to how well they bind to the hyaluronan around an egg cell. Mature, biochemically competent sperm bind to the hyaluronan where they are then isolated by the embryologist and used for ICSI.
The selected sperm is essentially the same as one that would be successful in the natural reproductive process. The more mature a sperm cell, the more able it is to bind to hyaluronic acid, meaning that it is better suited to fertilising the egg. The better sperm are in this respect, the better they are in all other respects, like fertilising the egg.
PICSI is suitable for everyone, but highly recommended in these particular cases: