Restriction Digestion of Phage DNA
jmone at MARAUDER.MILLERSV.EDU
Fri Sep 25 14:04:03 EST 1998
As a laboratory experiment, I and some students have isolated several
E. coli specific bacteriophages from untreated sewage. We have
isolated the phage DNA by treatment of purified phage preps by
treatment with proteinase K and SDS, followed by phenol-chloroform
extraction and precipitation with alcohol. The problem is that all of
the phage DNA preps appear to be completely resistant to restriction
digestion. I have tried several enzymes, including EcoRI, HindIII,
PstI and KpnI, and never a hint of digestion? What is going in here?
I generally run lambda DNA as a control to ensure that the enzymes
cut, so thats not the problem. The 260/280 is consistently > 1.5.
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