Comparative studies of natural and recombinant proteins by californium-252 plasma desorption and cesium ion liquid secondary ion mass spectrometry

Abstract

The relative molecular masses of five proteins in the 10–25 kDa range were successfully determined by 252Cf plasma desorption mass spectrometry (PDMS) and 35-keV Cs + liquid secondary ion mass spectrometry (LSIMS). Both techniques were comparable in demonstrating high mass accuracy and sensitivity, although LSIMS required a shorter analysis time than PDMS. The sensitivity of these methods was excellent, requiring only low-nanomole amounts of protein. The determination of relative molecular mass by the plasma desorption nitrocellulose method was less affected by the salt and buffer content of the sample, as these components could be effectively removed by washing.