electrophoresis of nuclear extracts

[DNewmeyer]

In article <8NOV199414465358 at aardvark.ucs.uoknor.edu>,
mccarthy at aardvark.ucs.uoknor.edu (MC_CARTHY,DAVE) writes:

**We are trying to fractionate proteins in human nuclear extracts in SDS
 polyacrylamide gels.  Althugh we observe sharp protein bands in 13%
 polyacrylamide, we have problems with gels that are below 10%
 polyacrylamide.  The protein forms vertical streaks along the edges of
 the lanes.  Equivalent amounts of protein from E. coli extracts do not
 show this sensitivity to polyacrylamide percentage in the same gels.**

It sounds like you may have a lot of DNA in your nuclear extracts. Try
adding a small amount of micrococcal nuclease or Dnase I to your samples
before loading.

Don Newmeyer
La Jolla Institute for Allergy and Immunology