Separate DNA fragments of same length

Brian J. Baumgartner brianb at
Fri Feb 5 20:46:31 EST 1993

I mentioned screening the PCR products from bacterial colonies by PCR
(article 4361) .
 My fingers were typing faster than my brain was thinking.  Instead just
do minipreps of the colonies and screen by Southern hybridization with the
oligos as described.  I am assuming you have no information on the
sequences between the PCR primers also.  If you have sequence information
you could of course design specific olignucleotide probes.  Once you pick
some interesting clones you will still have to sequence them at some point...
Another bizarre idea (it's getting late)... Use your degenerate primers at
one end and your selective oligos at the other end as PCR primers to
screen the recombinants; the unique oligo at one end should provide
selectivity (see, I knew there was a way to use PCR to screen your colonies!)

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