By Anonymous on Friday, October 4, 2002 - 03:11 pm:
Hi,
Has any of you heard about a detector that can do molecular sizing? I remember that company or that detector named with visco- something.
Thanks.
By Anonymous on Friday, October 4, 2002 - 03:22 pm:
If you use a viscometer in tandem with an RI or ELSD detector, you can do molecular sizing.
By H W Mueller on Sunday, October 6, 2002 - 11:41 pm:
Check
http://viscotek.com
There are others, like
ProteinSolutions, http://www.protein-solutions.com
Polymer Laboratories
postnova analytics, http://www.postnova.com
Precision Detectors
Wyatt Technology
Be careful, though, some companies claim things the mashines canīt deliver. If I understand the situation correctly you need a dynamic light scattering device to get at "theoretical" radii, apparently to get at MW + radii one needs the three detections mentioned by 2nd Anon.
By Anonymous on Monday, October 7, 2002 - 12:46 pm:
It sounds like for polymers and proteins. Is there any way to discard molecular weight over 1000 by any means?
By Anonymous on Monday, October 7, 2002 - 01:57 pm:
I think Pierce makes Molecular Weight Cutoff Centrifuge Tubes. It separates your sample by centrifuge into 2 portions depending on the molecular weight cutoff you choose. You could probably inject the small molecular weight fraction then. Just my thought, don't know if it would work.
By H W Mueller on Monday, October 7, 2002 - 11:29 pm:
You are looking for ultrafilters? Check amicon (Millipore), Whatman, Sartorius, Vivascience, etc.
Centrifuge filters are generally easiest to use. If you want to use ultrafilters to prove molecular size, remember that the relationship between molecular weight and "size" (3D) is complicated.