help! pure probes for f.i.s.h.

[gedmunds at kean.ucs.mun.ca]

      i am concerned that my probes are not pure enough for f.i.s.h.,
giving poor hybridization on chromosomes. they are purified by mini
preps. should i be using CsCl gredients(morer time consuming) or may 
i use a better quality mini-prep?

thanks for your time