Intracytoplasmic sperm injection 153187 215514501 2008-05-28T15:16:51Z A5b 722418 link to ru:~ [[Image:Icsi.JPG|thumb|right|250px|Oocyte is injected during ICSI]] '''Intracytoplasmic sperm injection''' ('''ICSI''', pronounced "eeksee"<ref>[http://www.drmalpani.com/oligospermia.htm drmalpani.com]</ref>) is an [[in vitro fertilization|''in vitro'' fertilization]] procedure in which a single [[spermatozoon|sperm]] is injected directly into an [[ovum|egg]]. This procedure is most commonly used to overcome male [[infertility]] problems, although it may also be used where eggs cannot easily be penetrated by sperm, and occasionally as a method of in vitro fertilization, especially that associated with [[sperm donation]]. The procedure is done under a [[microscope]] using multiple micromanipulation devices ([[micromanipulators]], [[microinjectors]] and [[micropipettes]]). A holding pipette (on the left of picture) stablizes the mature [[oocyte]]. From the opposite site a thin, hollow needle is pierced through the [[oolemma]] and into the inner part of the oocyte. It is loaded with a single sperm that will be released into the oocyte. The pictured oocyte has an extruded [[polar body]] at about 12 o'clock indicating its maturity. After the procedure, the oocyte will be placed into cell culture and checked on the following day for signs of [[fertilization]]. In natural fertilization sperm compete and when the first sperm enters the egg cell, the egg cell blocks the entry of any other sperm. Concern has been raised that in ICSI this sperm selection process is bypassed and the sperm is selected by the embryologist without any specific testing. However, in mid 2006 the FDA cleared a device that allows embryologists to select mature sperm for ICSI based on sperm binding to [[hyaluronan]], the main constituent of the gel layer ([[cumulus oophorus]]) surrounding the oocyte. The device provides microscopic droplets of hyaluronan hydrogel attached to the culture dish. The embryologist places the prepared sperm on the microdot, selects and captures sperm that bind to the dot. Basic research on the maturation of sperm shows that hyaluronan-binding sperm are more mature and show fewer DNA strand breaks and significantly lower levels of [[aneuploidy]] than the sperm population from which they were selected. There is some suggestion that [[birth defects]] are increased with the use of IVF in general, and ICSI specifically. It is hoped that use of new device (PICSI) will lower the apparently elevated level of birth defects associated with ICSI.(see section of [[IVF]] discussing birth defects) == See also == * [[Reproductive technology]] * [http://www.epigenome-noe.net/ The Epigenome Network of Excellence (NoE)] * [http://www.hfea.gov.uk/ The Human Fertilisation and Embryology Authority (HFEA)] ==References== <references /> [[Category:Fertility medicine]] [[de:Intrazytoplasmatische Spermieninjektion]] [[fr:ICSI]] [[it:ICSI]] [[nl:Intracytoplasmatische sperma-injectie]] [[pt:Microinjecção intracitoplasmática]] [[fi:Mikrohedelmöitys]] [[ru:ИКСИ]]