[RASMB] maximum smax& low MW

[John Correia]

I have done experiments on microtubule samples in excess of 5000 s at
1-3 K - a combination of C(s) and WD-DCDT work well for analysis.
 
I did notice that my XLA did not seem to like calibrating at 1000 rpm
and I had to calibrate at 3 K and then slow the speed to 1 K to maximize
the number of scans.  This may not be a unuversal problem.  It was also
helpful to only run one sample at a time or to scan a narrow region of
the cell to maximixe data acquisition (& thus using WD-DCDT analysis).
 
It is worth noting vanHolde & Baldwin (1958) measured the s value of
sucrose & Yphantis measured the MW of air (unpublished) by sealing only
one sector of a double sector cell & collecting interference data.  For
A + B system the issue may be more the fractional change in MW than the
absolute change.
 
 
 
 
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 Dr. John J. "Jack" Correia
 Department of Biochemistry
 University of Mississippi Medical Center
 2500 North State Street
 Jackson, MS  39216
 (601) 984-1522                                 
 fax (601) 984-1501                             
 email address: jcorreia at biochem.umsmed.edu     
 homepage location: http://biochemistry.umc.edu/correia.html 
 dept homepage location:    http://biochemistry.umc.edu/ 
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>>> "Qin Zou" <heat-capacity at indy.rr.com> 01/25/05 08:31PM >>>

Dear all,What is the maximum smax that can be used in c(s) analysis ? I
have tried 614s but the program crashed if smax is larger than that. So
if one wants to look at fairly large particle like John Philo did with
adenovirus, sedfit is not the good choice? Also, what would be the good
rotor speed if one wants to look at the particle size of 5-7MDa?  John
Philo used 1200-3000 rpm for 150MDa. Thanks for any input. Chin ZouEli
Lilly and Company
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