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 Dec 4th 2004<http://www.mail-archive.com/ccp4bb@jiscmail.ac.uk/msg08490.html> . Hope this helps Hari
On Mon, Jan 25, 2010 at 6:14 AM, Florian BrŸueckner < f.brueck...@imperial.ac.uk> 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 > > -- > --------------------------------------------------------------------------- > > Dr Florian Brueckner > MPL Group (Prof So Iwata), Imperial College > Diamond Light Source Ltd > Diamond House, Harwell Science and Innovation Campus > Didcot, Oxfordshire > OX11 0DE > England > > Phone (Office): +44-1235-77-8465 > Phone (Lab): +44-1235-77-8794 > Email: f.brueck...@imperial.ac.uk >
