title: Sodium and calcium localization in cells and tissues by precipitation with antimonate: a quantitative study.
abstract: Komnick's antimonate technique, which was devised to localize Na+ in cells and tissues, was studied quantitatively. Some modifications, as well as its application to Ca2+ localization, were also investigated. We combined measurements of Na+ and Ca2+ retention in plant roots during the various procedures, electron microscopy, autoradiography, and semiquantitative X-ray microanalysis. We were able to show that (at least in barley roots) antimonate does not precipitate at all with Na+, irrespective of the Na+ content of the tissue or the method of antimonate application. (Even during precipitative freeze dissolution or after freeze drying, no Na+ is precipitated.) By means of Komnick's antimonate technique Ca2+ is trapped within the tissue, but only after serious dislocation. Perspectives for reliable localization of diffusible ions in cells and tissues, by precipitation simultaneously with conventional fixations, are bad.
mesh_terms: D000965:Antimony; D001345:Autoradiography; D002118:Calcium / Q000032:analysis*; D002523:Edible Grain / Q000032:analysis*; D006651:Histocytochemistry; D001467:Hordeum / Q000032:analysis* / Q000648:ultrastructure; D012964:Sodium / Q000032:analysis*
chemical_list: D000965:Antimony; D012964:Sodium; D002118:Calcium