Monoclonal Antibody Analysis by Microfluidic Modulation Spectroscopy in a Complex Formulation Buffer

The MMS technology provides significant increases in sensitivity, dynamic range, and accuracy for the determination of protein secondary structure relative to conventional mid-IR and far-UV CD techniques. The analyzer utilizes a tunable quantum cascade laser to generate an optical signal over 100x brighter than the conventional sources used in FTIR spectroscopy. Brighter sources also allow the use of simpler detectors without the need for liquid nitrogen cooling. Additionally, the sample (protein) solution and a matching reference buffer stream are automatically introduced into a microfluidic flow cell, and the two fluids are rapidly modulated (1-4 Hz) across the laser beam path to produce nearly drift-free background compensated measurements. In this note, a native monoclonal antibody was measured by MMS in a complex buffer formulation at concentrations ranging from 1 to 150 mg/mL.