ELEMENTAL MICROANALYSIS OF FIBROBLASTS BY A SCANNING PROTON MICROPROBE AND APPLICATION TO MENKES DISEASE

A scanning proton microprobe has been used for the elemental microanal ysis of individual fibroblast cells. Both normal fibroblasts and fibro blasts cultured from patients with Menkes' disease, an X-linked geneti c disorder known to be associated with defective copper metabolism, we re examined by the probe. The cells were cultured on a thin ultra-clea n nylon foil and retained on that surface for analysis. The focused hi gh-energy proton beam was used to irradiate selected individual cells and elemental information was derived from X-ray and backscattered pro ton data. The sensitivity of the scanning proton microprobe to trace c oncentrations of heavy elements has allowed this elemental information to be used to identify individual cells as being either normal or a M enkes' mutant. The cell identification was based on the application of discriminate analysis to a data set formed from the ratios of copper to each of the macroelements present in the cell. This method of cell identification offers the promise of rapid diagnosis of Menkes' diseas e.