[sci.bio] Isolation of single-stranded DNA

diaz@aecom.YU.EDU (Daniel Diaz) (11/05/87)

In an attempt to avoid the complications of probe renaturation during S1
nuclease mapping of transcription start sites, I wish to easily isolate
single-stranded DNA from labeled duplex.  The new Guide to Molecular
Cloning Techniques put out by our friends at Methods in Enzymology has
not been helpful in this regard.  Although helpful, I've found the book
in need of excision repair.

Electrophoresis in polyacrylamide, 7M urea has been used by some, but I
don't know how well it works.  Recloning into m13 would be easiest, but
time-consuming.  Please send any suggestions via email.
-- 
      dn/dx      Dept Molecular Biology   diaz@aecom.yu.edu
     Dan Diaz           AECOM           "I've met Craig Werner"      

Mitchell_K_Hobish@cup.portal.com (11/10/87)

Have you considered cesium chloride (or the equivalent) ultracentrifu-
gation?  It used to work well for me when isolating polyoma or SV-40
DNA in supercoiled, open circle, nicked, etc. forms...

Mitchell_K_Hobish@cup.portal.com
CIS: 70320,257
MCI Mail: MHOBISH
GEnie: MitchH
DELPHI: MHOBISH

diaz@aecom.YU.EDU (Dizzy Dan Diaz) (11/13/87)

In article <1370@cup.portal.com>, Mitchell_K_Hobish@cup.portal.com writes:
> Have you considered cesium chloride (or the equivalent) ultracentrifu-
> gation?  It used to work well for me when isolating polyoma or SV-40
> DNA in supercoiled, open circle, nicked, etc. forms...

CsCl does not quite suit the purpose I had in mind.  I was interested in
separating strands of 5' labelled DNA frgaments < 1kb long.  CsCl by
itself would be unsuitable for large-scale preparations anyway since
CsCl it nondenaturing.  Alkaline gradients would be best for that
purpose.  Thanks for the suggestion anyway.
 

-- 
      dn/dx      Dept Molecular Biology   diaz@aecom.yu.edu
     Dan Diaz      Albert Finkelstein College of Quackery