Path: utzoo!utgpu!watserv1!watmath!att!pacbell.com!ucsd!usc!apple!bionet!PUCC.PRINCETON.EDU!B_FOLEY%UVMVAX From: B_FOLEY%UVMVAX@PUCC.PRINCETON.EDU Newsgroups: bionet.molbio.methds-reagnts Subject: M13 in XL1-Blue E.coli Message-ID: <9012202321.AA12204@genbank.bio.net> Date: 20 Dec 90 21:21:00 GMT Sender: daemon@genbank.bio.net Lines: 13 Hi! I am having trouble growing M13 phage in the E.coli strain XL1-Blue from Stratagene. I get nice clear and dark blue plaques when plating with this strain, but when I try to isolate ss-DNA from a 40ml culture grown 4-6 hours (as per Maniatis manual) I get a very very low yeild of phage particles. XL1-Blue has virtually the same genotype as the JM101-JM109 strains. My titer of virus in 1ml cultures grown for 4-6 hours is usually greater than 10 to the tenth pfu per milliliter, indicating that it CAN propagate phage. Has anyone else had trouble getting ss-DNA from M13 because of minor differences in E.coli strains? Brian Foley B_FOLEY@UVMVAX.BITNET