Dear All:
This is off topic but I would rather try here first.
I am wondering whether Dnase could be a contaminant during the nickel
affinity purification of a his.tag protein expressed using pET29b. The
cells were disrupted using sonication only. Very high yield (30 mg/liter
of cell culture). FPLC purification. SDS-PAGE shows a singe band even
when overloaded. Silver staining is in progress.
The protein I am interested in does not have any similarity to Dnase.
However, when treated with supercoiled dna, the dna is degraded as
efficiently as with Dnase I from Sigma.
I am looking for ways to show that my preparation does not have any
Dnase contamination. I would appreciate it very much if someone points
me in the right direction.
Thanks a lot
Subbu
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