This is a copy of the slides presented at the meeting but not formally written up for the volume.

Size exclusion chromatography (SEC) and dynamic light scattering (DLS) are two technologies common to protein laboratories. SEC is routinely used for purification, identification, and quantification of protein mixtures, while batch DLS is routinely used for pre-column size & polydispersity measurements, along with aggregate quantification. The coupling of DLS & SEC technologies has been difficult, due in large part to the fact that eluted protein sample concentrations tend to be well below the detection limit for most dynamic light scattering instruments. As highlighted and discussed in the paper presented here however, the latest generation of DLS systems, specifically the high sensitivity Zetasizer Nano from Malvern Instruments, has proven itself capable of handling this low protein concentration challenge. As a consequence, size exclusion chromatography systems can now be directly coupled with high sensitivity DLS instrumentation, thereby providing an “absolute” measure of the hydrodynamic size and minimizing the common headaches of SEC measurements such as packing material interactions and shape effects.