Aggregate Detection via Wicking and Electrophoresis

Protein drugs have recently emerged as powerful pharmaceuticals due to their high specificity, affinity and the fact that they are not readily metabolized because of their size and can therefore interact longer with their target sites as opposed to most synthetic drugs. It is therefore of primordial importance to make sure that those drugs are free of aggregates as the later may lead to rapid drug metabolism or serious side effects. Pharmaceutical companies have been investing in finding a rapid mean for aggregate detection and our research lab has undertaken this task by using two main processes: wicking and electrophoresis. Wicking in our experiments involves the motion of a degraded fluorescently labeled- antibody (known to have at least a dimer in addition to the monomer by size exclusion chromatography) through a Teflon coated capillary packed with sub-micron acrylamide-coated silica particles without any external forces using a phosphate buffer. The motion/separation is observed through a fluorescence microscope, the collected data converted into intensity versus time plot and then analyzed for correlation.

Up to this point in our investigation electrophoresis rather than wicking appears to provide the best and most reproducible separation. We intend to further this study by varying factors such as particle size, nature of the fluorescent label, buffer concentration and modification reaction time.