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

Antibodies are specialized proteins that function as an essential part of the immune system and usually target specific receptors, making them ideal for the development of drug candidates. They are members of a class of proteins known as immunoglobulins, typically with a molecular size near ~10nm. This preclinical characterization shows the advantages of dynamic light scattering (DLS) both as a standalone method and in conjunction with chromatographic separation. We show data demonstrating the effect of different storage conditions and sample treatment, leading to different size distributions. Behaviour as a function of temperature shows a clear melting or aggregation point, above which the molecules assemble into larger structures. Higher melting points are correlated with higher stability. Size distribution data may be compared with results obtained from analytical ultracentrifugation (AUC) ? but at much faster acquisition time of minutes instead of hours. We have also combined light scattering with chromatography to show the separation of antibodies and Fab fragments. Here, the resolving power of the separation method allows us to distinguish the fragments (about ~5nm size) from the ?intact? molecules. Dynamic light scattering is a versatile measurement technique and ideally suited as a metrology of choice for size and stability of nano-sized materials.