[RASMB] A question about sample preparation: dilution (20 fold) vs dialysis

[Yi-Ming_Li at hgsi.com]

Hi
I have a question about sample preparation for analytical
ultracentrifugation. I am going to run a sedimentation velocity experiment
to examine the size distribution of the samples. Due to the limit in sample
amount, I will directly dilute the sample (20 folds) in running buffer
instead of dialyzing it against running buffer.  This will make some
difference between the reference and the sample. I want to know whether
this is tolerable for sedimentation velocity experiment with absorbance
(280 nm and 230 nm) detection. The differences of sample buffer and running
buffer are in glycine, Tween 80 and sucrose concentrations as following:

Sample buffer: 1.9% glycine, 0.5% sucrose, 0.01% Tween 80

Running buffer: no glycine, 8% sucrose, 0.04% Tween 80

In both buffers, Tween 80 concentrations are over CMC (critical micelle
concentration).

Thanks!

Yi-Ming