X-Message-Number: 5057 From: Robert D Grahame <> Newsgroups: sci.cryonics Subject: Re: Frozen Dog Date: Fri, 27 Oct 95 18:43:34 GMT Message-ID: <> References: <46hcpg$> <> <46pe77$> In article <46pe77$> Yannis <"yannis"@yannis.seanet,com> writes: >Isn't the sperm at sperm banks kept frozen and then thawed for >use? Why is it that sperm stays viable and not other organs or >organisms? This is quite true. Also human egg cells, and even very early human embryos can be frozen indefinately. This is done routinely as part of some IVF fertility treatments. The main reason seems to be that sperm are single cells. With careful preparation the various problems with freezing any individual cell can be avoided by customising the procedure to that cells needs. The minute size also allows *very* fast freezing and thawing. To freeze an organ takes much longer, which causes one set of problems (such as cracking), and you also have to preserve the organ's structure of millions of cells of many different types linked together into a single complex machine. This is much harder, as the 'ideal' preservation technique varies greatly from one type of cell to another. This is purely my understanding BTW, I'm not qualified. -- Bob Grahame, Streatham, London. LAN Consultant -- Voice : +(44)181 764 6058 : PGP Key available -- Towel : 0d8'22"W51d24'16"N+29M Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=5057