Three ways to characterize a Mab with the ZMV
It might be micro by name, but the Zetasizer µV certainly is not micro by nature! Offering no fewer than three analysis modes, the Zetasizer µV could be one of the most powerful tools in your analytical arsenal. So, if you are keen on taking a multi-faceted approach to the characterization of antibody structure, stability and purity: read on!
Recently, I used the Zetasizer µV to characterize an ‘off the shelf’ antibody sample in three different ways and in a total analysis time of less than 24 hours. Starting the analyses was easy with cuvette mode. Within a few minutes, I had undertaken size and size distribution analyses to the conclusion that the antibody existed as a slightly polydisperse population of on average 5.4 nm in radius. Using the same sample, I set up an overnight experiment to probe the thermal stability of the antibody under these buffer conditions. In fact, I could use the aggregation point as a stability indicator to screen multiple buffer formulations. Remember: the higher the aggregation point the greater the stability!
Coupling of the Zetasizer µV to a chromatography system I learn that the 97% of the antibody sample comprises a 150 kDa molecule with a hydrodynamic radius of 5.7 nm and a glycosylation state of ~4%. The remaining 3% corresponds to a higher order oligomer with molecular weight of 300 kDa.
So, whether you want to confirm the oligomeric state of your antibody, quantify glycosylation, find the most stable formulation, assess the purity of a finalized product or all of the above: the Zetasizer µV is a versatile instrument that allows just that.