From owner-diagnostics@net.bio.net Tue Apr 04 23:00:00 1995 Path: biosci!ACADEM01.MTY.ITESM.MX!dsleal From: dsleal@ACADEM01.MTY.ITESM.MX ("M.C. Diana Sara Leal Klevezas") Newsgroups: bionet.diagnostics Subject: Re: PCR-related techniques for detecting food born pathogens. Date: 5 Apr 1995 08:08:39 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 42 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <01HOWV77I5Z60007RI@GW.AGR.CA> NNTP-Posting-Host: net.bio.net On 3 Apr 1995 DEBOER@pargva.agr.ca wrote: > Dear netters, > > A friend of mine is thinking of a project on application of PCR- > related techniques for detecting food borne pathogens in milk and > eggs. Despite the possible PCR-inhibitory substances in the DNA > extracts from raw samples, DNA from dead cells may give false > positive results. How can we solve this problem? > > Is there any related references? Any suggestion will be > appreciated. > > Xiang Li > > Agriculture Canada > Vancouver Research Station. > > Dr. Griffits, at the Food science department at the U. of Guelph, Ontario, Canada is working with Salmonella-contaminated eggs is a neat way. He constructed a Salmonella phage carrying and expressing a Luciferase gene, which is then injected into the eggs.If they glow,means that Salmonella is present and alive since it allows the expression of the selectable marker. I understand it's working nicely. The U of Guelph's phone number is (595) 8244120 (check the area code, I'm not possitive), the fellow's name is Mansell (or sounds like it) Griffits. For the milk problem we are writting a project about the detection of Brucella on milk samples. We have developed the protocol for the DNA extraction and PCR which is working quite fine. We have wondered if after pasteurization or other kind of processing there will be death bacteria to keep the test appearing possitive. Please, get your friend to contact us to share our ideas with him/her. Best Regards form Sunny Mexico Diana Sara Leal Klevezas Centro de Investigacion Biomedica del Noreste Instituto Mexicano del Seguro Social San Luis Potosi y 2 de abril, Col. Independencia Monterrey, N.L. tel and fax. (52) 344 4116 .