New method for quantitative mapping of metallic elements in tissue sections by electron probe microanalyser with wavelength dispersive spectrometers.

Abstract

In this paper, we have proposed a new method that gives quantitative distributions of metallic elements in a tissue section by electron probe microanalyser equipped with wavelength dispersive spectrometers. Its principal merit is the clear expression of element distribution with micrometer resolution in typically prepared section samples for routine histopathological diagnosis. By analysing thin standard films containing metallic atoms of interest, it was confirmed that the detection limit is about 1 x 10(6) atoms microm-2. This value corresponds to 100 microg g(-1) (dry weight) in case of tissue section of 2 microm thickness. Furthermore, for copper, iron and aluminium, the exact linear relationship between the amount of metallic atoms and the characteristic X-ray intensity was established in the range up to 15 x 10(6) atoms microm(-2). The element maps of tissue sections from patients with Wilson's disease proved that the copper levels in analysed areas were not homogeneous and indicated abnormal accumulation in some portions. These results confirmed the usefulness of this method for histopathological diagnosis.