Dear Markus



Please find a response from one of our specialists - feel free to contact him for more information (his contact details are at the bottom of this email as he is not on the bulletin board).



The primary factors I would consider are the type of material in the column and also the pore size/ effective molecular weight range. The pore size will dictate the selectivity of the separation, you mention you are looking at large proteins (MDa) so a column with larger pores will give you a higher effective molecular weight range and better resolution. The molecular weight range for each column is published by each manufacturer, I have listed these below: 



SEPAX UNIX-C 5,000-1,250,000 (https://sepax-tech.com/Unix-C.php) 

BioZen SEC-3 10,000-700,000 (http://www.phenomenex.com/products/detail/biozen) 

Waters BEH450 or XBridge450  SEC 100,000-1,500,000 (http://www.waters.com/waters/partDetail.htm?partNumber=186006852) 



The SEPAX and BioZen are both silica materials so high efficiency and good pressure tolerance but also with the potential for proteins to stick requiring high salt. The Xbridge and BEH are hybrid particles (hybrid of a silica and polymer) giving reduced secondary interactions but retaining the high efficiency and pressure tolerance of silica. so may be a nice middle ground between silica and polymer.   



I was also wondering if you working with a HPLC system or a UPLC system? The extra column volume has a big impact on resolution of peaks in SEC if you are working on HPLC 7.8mm i.d. column will help to absorb some of the system dispersion, if your system is a well optimised UPLC (1290, ACQUITY etc) 4.6mm will be fine. 



Richard Robinson 

Biopharm Specialist

UK and Ireland 	



[T] +442082386100   

[M] +447824326822   

[W] www.waters.com 

[E] [log in to unmask] 





-----Original Message-----

From: CCP4 bulletin board <[log in to unmask]> On Behalf Of Markus Heckmann

Sent: 26 April 2018 17:04

To: [log in to unmask]

Subject: [ccp4bb] size exclusion columns



Dear all,



We are looking for a size exclusion chromatography column

(silica-based) for protein purification prior to a MALS-detector. We looked for (www.waters.com BEH-450), Sepax (Unix-C 300) and Phenomex (BioZen SEC-3).  Any 'column' tips or recommendations when dealing with large proteins (MDa)?



Many thanks

Markus