[RASMB] glycerol and the formation of gradients

[Jack Kornblatt]

Dear All
Back in 2003 Borries Demeler made the following suggestion to a question:

"Marcello,

that's quite a bit of glycerol. Depending on the speed, I'd be concerned
about building up a glycerol gradient inside your velocity experiment
which would also give a gradient of density and viscosity, causing the
sample to slow down towards the bottom of the cell (it hits a glycerol
cushion?). Just another variable to think about. One thing you might 
want to do to verify this is to run glycerol against water to see if the 
effect is large enough ito worry about at the speed you are running it. 
Should be possible with and XLI.

Regards, -Borries"

I have searched the archives and have done a day's search of the 
literature but I've not found any sign that people have taken Borries' 
suggestion to heart. Has anyone out there measured the sedimentation of 
glycerol? We have an XL-I and plan to do the experiment tomorrow but it 
would be very nice to have something to compare the results to. This 
presumes, of course, that there are results. If there are, I'll let you 
know.

On reflection, Jim Cole, might have the data. His 1996 paper on glycerol 
effects still impresses one.

best to all
jack (kornblatt)