Hello everybody, I have questions to ask for your help.
I have used GeneClean to recover DNA from agarose. After eluting the DNA
in TE, I discover quite serious DNA degradation from gel electrophoresis.
I suspect the sources of contamination: TE or GlassMilk or both. In order
to eliminate the problem, I autoclave the TE and the question is, is it
possible to autoclave the GlassMilk without affect the DNA-binding
activity? Is there other possible sources to get the contaminant?
The second question is what density of the E.coli (OD600) suitable
to make competent cells? Is it necessary that the higher OD (e.g. 6.0),
the lower transformation efficiency as a result?