From owner-cellbiol@net.bio.net Tue Dec 10 22:00:00 1996 Path: biosci!agate!spool.mu.edu!uwm.edu!news-peer.gsl.net!news.gsl.net!usenet.eel.ufl.edu!warwick!lyra.csx.cam.ac.uk!hgmp.mrc.ac.uk!news From: sghk100@sghms.ac.uk (David Winterbourne) Newsgroups: bionet.cellbiol Subject: Re: dissolving xathine Date: 11 Dec 1996 11:15:31 GMT Organization: St. George's Hospital Medical School Lines: 21 Message-ID: <58m54j$akl@mercury.hgmp.mrc.ac.uk> References: NNTP-Posting-Host: dwinterbpc1.sghms.ac.uk Mime-Version: 1.0 Content-Type: Text/Plain; charset=US-ASCII X-Newsreader: WinVN 0.99.6 In article , Srikumar M. Raja says... >I am having some problems with dissolving xathine in water at conc. 10 >mg/ml for tissue culture. Xanthine is sparingly soluble in water (~0.4mM = ~0.06mg/ml). Salts of xanthine are more soluble than the free base. It is possible to get fairly high concentrations into solution by raising the pH. I prepare 40mM stock solutions in 0.1M NaOH. As long as your final concentration in medium is below ~2mM this has little effect on the pH of the medium. Above this final concentration it will precipitate in the medium. -- Dr. David Winterbourne Department of Surgery St George's Hospital Medical School, London SW17 0RE, England Tel: 0181-725-5581 Fax: 0181-725-3594 .