X-Message-Number: 8433 Date: Fri, 1 Aug 1997 05:30:13 -0700 (PDT) From: Doug Skrecky <> Subject: Re: CryoNet #8429 - #8432 In Message #8429 Brian Wowk <> wrote: > About adonitol in particular, adonitol (1,2,3,4,5 penta- > hydroxypentane) is a huge molecule that costs $2 per gram. > Although I haven't consulted Doug's permeability reference > yet, it's almost certainly going to be less permeant and > more viscous than glycerol. And glycerol is already almost > intolerably viscous and non-permeant for cryoprotection by > perfusion (as distinct from cryoprotection of cell suspenstions > in solution). > Adonitol is indeed more viscous than glycerol. That's the inevitable price you have to pay for cryoprotection that is stable (or glassy) at relatively high temperatures. Adonitol has a molecular weight of 152, while glycerol's is 92.09. Adonitol perfuses well for a molecule of its size because its cross section is no larger than that of glycerol, so it can pass through pores in cell membranes. Sorbitol has a molecular weight of 182.17 and unfortunately has a larger cross section, so it diffuses very slowly. However at least sorbitol is cheap. I will make some inquiries to see what the best price for adonitol is. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=8433