For ten years while teaching molecular biology lab courses, I have had the
students digest their Drosophila genomic DNA preps with RNAseA to
demonstrate the RNA contaminants. Invariably, this treatment also degrades
the high molecular weight DNA. This same RNAseA has never caused any
degradation of plasmid DNA in overnight restriction enzyme digests, so I
don't believe there is significant DNAse activity.
Does this reflect something about Drosophila DNA that I am not aware of
(for example, that the RNA primers are ligated in and not removed)? Or is
it simply another exiperment that won't work on demand in a lab class?