[RASMB] SDS sedimentation

[Tom Laue]

Hi all-
The following information is thanks to John Harlan:

The vbar for SDS (listed as lauryl dodecyl sulfate) of 0.864 from 
Tanford et al., Biochemistry 13:2369 (1974).
SDS is an ionic detergent, the aggregation number, hence micellar mw 
will like vary pretty substantially with ionic strength, getting larger 
as ionic strength increases.  Mysels and Princen (1959) J Phys Chem 
63:1696, are cited in a Calbiochem pamplet on detergents, as having 
shown an ~60% increase in aggregation number of SDS micelles as [Na+] 
went from the range of 0.0-0.1M to 0.1-0.2M, using light scattering 
measurements.

Some information on specific ion effects on the cmc are found in:
Effect of electrolytes on the physicochemical behaviour of sodium 
dodecyl sulphate micelles.     Dutkiewicz, E.; Jakubowska, A.    Adam 
Mickiewicz  Colloid and Polymer Science  (2002),  280:1009-1014.
Best wishes,
Tom

-- 
Department of Biochemistry and Molecular Biology
University of New Hampshire
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E-mail: Tom.Laue at unh.edu
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