From owner-diagnostics@net.bio.net Thu Mar 23 22:00:00 1995 Path: biosci!bcm!cs.utexas.edu!news.sprintlink.net!uunet!newsflash.concordia.ca!canopus.cc.umanitoba.ca!zeno.ibd.nrc.ca!mansfield From: mansfield@zeno.ibd.nrc.ca (Jim Mansfield) Newsgroups: bionet.diagnostics Subject: Re: low boiling point Date: 24 Mar 1995 17:38:34 GMT Organization: NRC Institute for Biodiagnostics Lines: 28 Message-ID: <3kv02q$fon@canopus.cc.umanitoba.ca> References: <01HOGBWKERZ6001C7V@GW.AGR.CA> NNTP-Posting-Host: zeno.ibd.nrc.ca In article dsleal@ACADEM01.MTY.ITESM.MX ("M.C. Diana Sara Leal Klevezas") writes: > >If I'm wrong regarding the pressure building up in warm tubes, the >possibilities are even more exciting, here is the idea: The water boils >because the molecules get excited enough to do so. If less energy is >needed to boil the water, less energy might be needed to break the >hidrogen bonds between DNA strands, which means that under those >circumstances, one might need lower temperatures to reach DNA melting >point. If this is true, the consecuences are that your Taq will last >loger!!!. Thankfully, hydrogen bonding and similar prcesses are not affected by pressure changes of the magnitute we are discussing - otherwise life as we know it would not be possible in Peru at all! The reason less energy and, hence lower temperatures, are needed at high altitudes is the vapour pressure of the liquid does not need to be as high before it matches atmospheric pressure. As the temp. of a liquid rises, so does its vapour pressure. Once it reaches atmospheric pressure, voila, boiling. Putting a lid on the vesselwill raise the pressure of the gas over the liquid, raising its boiling point. -Jim -- --------------------------------------------------------------------- Jim Mansfield internet: mansfield@ibd.nrc.ca Institute for Biodiagnostics, NRCC phone: (204) 984-5191 http://www.ibd.nrc.ca/~mansfield/ fax: (204) 984-5472 .