Ultrastructural Localization of Ions. II. X-Ray Analytical Verification of Silver Precipitation Products and Distribution of Chloride in Mesophyll Cells of Barley Seedlings

Abstract

The ultrastructural localization of Cl- by means of a silver precipitation technique has been verified by means of X-ray analytical electron microscopy (EMMA-4 electron microscope plus KEVEX energy dispersive analyser). It was shown that the localization method was specific for Cl- in the case of electron-dense deposits in chloroplasts, plasmodesmata and plasmalemma of barley mesophyll cells. It was pointed out that the use of nitric acid rinses in order to remove non-specific deposits of silver phosphates and carbonates has pitfalls and that the precipitation technique should always be used in conjunction with X-ray microprobe analysis.