Path: utzoo!utgpu!water!watmath!uunet!ig!bionet-20.bio.net!GORDON.BRADSHAW From: GORDON.BRADSHAW@BIONET-20.BIO.NET (Toby Bradshaw) Newsgroups: bionet.molbio.methds-reagnts Subject: Re: Uniform gels for reading long sequences Message-ID: <12412697193.39.GORDON.BRADSHAW@BIONET-20.ARPA> Date: 8 Jul 88 16:22:08 GMT References: <12412284971.17.EROSENTHAL@BIONET-20.ARPA> Sender: daemon@presto.ig.com Lines: 13 Eric: The blur you see at 300-400 bases is due to an anion formed by the glycerol in the Sequenase enzyme when electrophoresed in a buffer containing borate ions. This anion migrates at that position in the gel, screwing up the resolution. I don't normally care about it, but if you do, I would suggest trying a buffer other than Tris-borate or (probably too much trouble) a spin column or precipitation to eliminate the glycerol. As for the wedge gels, a longer fixing time will help since its the failure to remove the hygroscopic urea that makes gels stick to film. Hope this helps. Toby Bradshaw -------