HMW Standards for SEC

[ginebra]

Hi!

I am new in this field and dealing with large proteins/complexes up to 8MDa. Currently I am using a standard kit (29-669 kDa) whereas Thyroglobuline COULD also appear as 1300kDa tetramer. Blue Dextran (if not so polydisperse) with 2MDa could be another point.
I am looking for standards I can use to calibrate the column for the big ones. I have not really found any literature on this topic. What came to mind (so far) is the vonWillebrand factor but I do not know whether its available and monodisperse in size.
What could I use to calibrate my column for such large proteins? Are defined PEG-sizes an option? Any other ideas?

cheers,
Christian

[Gerhard Kratz]

Please try to contact the company Ludger Ltd in the UK. So far I know they are producing high MW dextran standards. Go on www.ludger.com and good luck.

[ginebra]

Hi Gerhard,

thanks for the advice. I have posted an inquiry to them. Lets see what comes....

Cheers,
Christian

[SeanAustin]

Hi

If you are measuring protein molecular weights you do not want to calibrate your column with polysaccharides - they behave differently in the SEC system (a polysaccharide and a protein of the same molecular weight will appear at two different retention times since proteins generally have a more compact structure). So if you are interested in proteins, better to use protein standards.

PSS in germany might be a good place to look: http://www.polymer.de/ and if you don't find anything there they might be able to point you in the right direction.

Good luck