A post-doc in our lab and myself have had the following strange problem:
Working with Rhodococcus total DNA from three strains, we can't clone
the stuff! (Into E.coli HB101) We used the procedure from Current Protocols
for DNA isolation, which includes a phenol/chloroform extraction, CTAB
extraction and a CsCl-EtBr gradient. One would thinkt hat after all that
purification, the DNA would be pretty darned pure, right? Wrong: after all
that, a subsequent phenol/chloroform extraction shows leftover polysaccharide.
Stranger still, whatever is interfereing does not seem to be doing it
at the ligation step (into pHC79). The ligate checks out fine.
Has anyone else had this problem? Does anyone know something
about Rhodococcus DNA that we don't?