Hello Florian,We routinely measure membrane protein samples in detergent with much problem on the nanodrop. The concentration of detergent is often many times the CMC . We have found the drop does form quite well as long as the surface is clean.
Often this can be easily achieved by repeated "buffing" of the surface with a "kimwipe".
Also at moderate protein concentrations used with crystallography i.e the 6-25 mg/ml range with 5 to 20 mM detergent ( CMC around 0.7 mM) , the A280 measurement is seemless ..you put the drop there ( 3 to 5 µl ) and read the A280. Only about one out of ten times , the drop collapses and fails to give a good reading. Then you just buff the surface , and repeat the reading.
So in summary , there is no problem. I would also read a ccp4bb discussion on this topic which occurred on
[log in to unmask]">Dec 4th 2004.
Hope this helps
Hari
On Mon, Jan 25, 2010 at 6:14 AM, Florian BrŸueckner
<[log in to unmask]> wrote:
Dear all,
can anyone share experience with measuring membrane protein
concentration in detergent containing buffer with a nanodrop photometer
e.g. Thermo Scientific ND2000. Specifically, does the reduction in
surface tension caused by the detergent pose any problems?
Thanks!
Cheers
Florian
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Dr Florian Brueckner
MPL Group (Prof So Iwata), Imperial College
Diamond Light Source Ltd
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