Isothermal calorimetry of a monoclonal antibody using a conventional differential scanning calorimeter.

It has been shown that isothermal calorimetry is able to provide critical information regarding the kinetics of denaturation/aggregation of monoclonal antibodies at temperatures below Tm. Those measurements, however, required sophisticated specialized instrumentation. Here, we demonstrate that similar measurements can be performed using widely available conventional differential scanning calorimeters (DSC) when operated in isothermal scan mode. The denaturation/aggregation kinetics of the anti-HIV monoclonal antibody VRC07-523LS was measured by isothermal DSC at ten degrees below Tm. It is shown that a readily available instrument provides similar kinetic information and can become an important tool for determining the long term stability of biologics.