Comparison of various nano-differential mobility analysers (nDMAs) applying globular proteins

The demand for analysis of nanosized particles and assemblies of biologic and inorganic origin has increased in the recent decade together with the growing development of biotechnology and nanotechnology. Recent developments of electrostatic differential mobility analysis ( DMA) provide an excellent characterization tool in the nanometer size range. With an increasing number of available nano-DMA ( nDMA) systems, the question of data comparability and implementation of possible calibration procedures arise. Here we present analysis of proteins in a range between 3 nm ( 5.7 kDa) and 15nm ( 660 kDa) with five different nDMA systems. Results show differences in the obtained sizes up to 15% between different nDMA systems, which consequently leads to the conclusion that a calibration procedure for each nDMA is necessary when applying such systems for the analysis of nanoparticles with respect to size and molecular mass.