From owner-cellbiol@net.bio.net Wed Feb 26 22:00:00 1997 Path: biosci!rutgers.rutgers.edu!uwm.edu!cs.utexas.edu!howland.erols.net!rill.news.pipex.net!pipex!warwick!leicester!usenet From: "Dr E. Buxbaum" Newsgroups: bionet.cellbiol Subject: Re: Problem with nonspecific antibody binding Date: 27 Feb 1997 11:12:24 GMT Organization: University of Leicester (PCFS User) Lines: 16 Message-ID: <5f3q6o$67s@falcon.le.ac.uk> References: <19970226003101.TAA15516@ladder02.news.aol.com> NNTP-Posting-Host: pc47.msb.le.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 1.22 (Windows; I; 16bit) divernlb@aol.com (DiverNLB) wrote: The problem I am having is nonspecific binding of the >secondary antibody (conjugated to fluorescein), leading to strong >false-positive signals. I have tried blocking with bovine serum albumin, >fetal bovine serum, and horse serum, with little or no effect. You could try to include fish skin gelatine (Sigma) into your solutions, this sometimes helps. Be warned though, this is a realy messy (though not dangerous) material. Are you sure that it is realy the secondary, rather than the primary antibody that is causing the problem? In this case you may want to change the source of the antibody (different company, different species). You may even label the primary antibody directly, if you have enough of it. .