Path: utzoo!utgpu!watserv1!watmath!att!news.cs.indiana.edu!bionet!wums.bitnet!WILSON_R From: WILSON_R@wums.bitnet Newsgroups: bionet.molbio.methds-reagnts Subject: PCR cloning Message-ID: <9012132014.AA02624@genbank.bio.net> Date: 13 Dec 90 20:04:00 GMT Sender: daemon@genbank.bio.net Lines: 25 Hi! I thought I might say a word or two in response to recent inquiries about cloning PCR products. As far as the concept of Taq DNA pol leaving an overhanging A residue at the 3' end of PCR products, I'd say that the A (or some other base) is not there in some percentage of the DNA. You certainly can clone PCR products in a blunt end site with very good efficiency with no other post- (or pre-) PCR treatment than kinasing. If we add T4 DNA pol to the PCR mixture immediately following PCR, and incubate at 37 degrees for 15 minutes, cloning efficiency is doubled. Thus, your overhanging base. A 1-hour treatment at 15 degrees with a few units of Klenow seems to work fine also. You guys not wanting to spend the bucks on those TA cloning kits might want to consider this method. Good Luck! R. Wilson, St. Louis