[RASMB] peak in sedimentation velocity scans at high protein conc.

[John Philo]

Norbert,

Yes, Andy is right, this is due to deflection of the light beam by the
refractive index gradient caused by the boundary itself. The 3 mm pathlength
cells should allow you to go to 6 mg/ml, although you still will have issues
with data analysis due to the significant non-ideality effects.

John

-----Original Message-----
From: rasmb-bounces at rasmb.bbri.org [mailto:rasmb-bounces at rasmb.bbri.org] On
Behalf Of Norbert Muecke
Sent: Friday, October 28, 2005 4:29 AM
To: RASMB at server1.bbri.org
Subject: [RASMB] peak in sedimentation velocity scans at high protein conc.


Hi,
I have done some velocity runs at high protein conc. (up to 6g/l). A new
peak within the boundary could be observed. I have attached the scans of
three different concentrations. Absorbance was measured at 284nm. Any idea
of how to explain that phenomena would be appreciated.

Best regards
Norbert


Division Biophysics of Macromolecules, B040
German Cancer Research Center (DKFZ), TP3
Im Neuenheimer Feld 580
D-69120 Heidelberg, Germany