High resolution imaging and elemental analysis of PAGE electrophoretograms by scanning proton microprobe

Metal content of metalloproteins can be detected and even quantified by the PIXE–PAGE method. In this technique the proteins are separated by thin layer electrophoresis (by polyacrylamide gel electrophoresis (PAGE) in most cases) and the properly dried gel sections are analyzed by PIXE using “band-shaped” proton milli-beam. This PIXE–PAGE method was adapted for our scanning proton microprobe. The microPIXE–PAGE version provides two-dimensional elemental mapping of the protein bands. In addition, the fast continuous scanning reduces the risk of the thermal deterioration of the sample and the X-ray contribution from dust-impurities can be filtered out in the data evaluation process.