From: Jack Correia <jcorreia@fiona.umsmed.edu>
  To  : rasmb@bbri.eri.harvard.edu
  Date: Fri, 10 Mar 95 12:12:55 -0600

Surfactant + DNA is BIG

        Thanks for the input!  The obvious question is did it pellet out!  A 
simple test experiment was to do a 15 min. spin in an eppendorf (15K) and 
recover the sup.  The OD at 260 was completely gone!  When we have more 
material we'll repeat the vel. run at 3K and I'll tell you how big big is!  
The initial run was at 30K, and the investigator providing the material was 
"sure" of the micelle size.   I wasn't sure that a complex would float or 
sink, but sedimentation is the obvious answer now!   In the BPE buffer they 
use (PO4) we did monitor at 218nm and saw no changes in the surfactant left 
behind so all the micelles must quantitatively pellet.  The baseline with 
surfactant at 218 nm is rather structured with large dips and inflections, 
and identically shaped for two cells?  Scattering effects from the slit?

jack