Vector self ligation? - (Oct/19/2005 )

HI All,
i've a question abt self ligation, what should i infer if i get colonies in vector only plates but not in vector+insert, or if # of colonies in self lig. is much higher than V+I; does that mean any colonies in V+I could only be vector itself. in this case, i digested with BamHI and SacI sequentially, should not get any self ligation; and my insert is only 70bp.
i'll appreciate is someone could suggest some way of screening large # of colonies, i can't do restriction analysis of only site in between, it cuts insert.

thanks a lot
nbj

Your ligation most likely didn't work. You may have trouble isolating the small fragment. How are you doing this? IS it from a gel purification? As for your other question, you could do a PCR to screen your ligations. Look for protocols of this website for "colony PCR", it is a pretty standard technique.