The use of absorption difference at distant wavelengths for imaging elements in mammalian cells

Intracellular mapping of elements was performed for Cd or Hg loaded mammalian cells. X-ray contact microscopy with an electronic zooming tube were used for cell imaging at the resolution of 0.5 μm. The mapping was obtained by the subtraction between images taken at two different wavelengths. For both elements, pair of the wavelengths at 8.21 nm and 4.48 nm was adopted, because the absorption coefficients of Cd and Hg at 8.21 nm are smaller than those at 4.48 nm, while those of major elements in biological components such as C, N and O exhibit opposite nature. Subtracted data were compared with those for non-loaded cells. The results suggest that the present method is valuable for a new approach to image some kinds of elements such as Cd and Hg that have no absorption edge or have the absorption edge overlapped with those of major elements in this wavelength region