[RASMB] refraction line in the SV boundary

[Ariel Lustig]

Dear Nobert , dear Colleauges,
I just like  to add (as I worked  with the   model E /schlieren +abs. simultaneous,  many  years) and to emphasize what  J.Correia wrote, that this phenomena appears at  high MW's, and to the others who  wrote ...at  high  concentration as  Nobert discribed.
 Sure that it is a phenomea that pappens when the  light is deviated  too strong  out of the optical system so with  schlieren we get   a black line=no light. Reducing the  cell thickness as J Philo suggested is good  advise.Theoretically
it would not happen if  you enlarge  the diameter  of  the  lenses (practically impossible).
This  phenomena may occure also at not so high  concentration about  1/4  mgmL of  DNA or similar  nerrow 
boundaries where the   diffusion  constant is very  small and the  boundary  spreads slowly . In many  cases  it happens 
with  high molecular species where  normaly diffusion is  low but I would  say that it is a Diffusion dependent  phenomena! 
Also at the  beginning of a SE run it may happen, but it don't bother us as we do not  suffer from diffusion spreading  time, but  I believe that some  newcommers may stop such a run thinking that it was  acell-filling  error....yours ariel 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.rasmb.org/pipermail/rasmb-rasmb.org/attachments/20051028/047679a8/attachment.htm>