A high-resolution tungstate membrane label.

A new class of membrane labels was synthesized which contain a tungstate cluster (having 11 tungsten atoms) and an aliphatic organo-tin moiety with various chain lengths (C4, C8, C12, C18, C22). These molecules were found to insert into synthetic phospholipid vesicles and biological membranes (human red blood cell membranes). The tungstate clusters can be individually visualized in the high resolution STEM or seen en mass in thin-sectioned labeled membranes in the CTEM. These new labels should provide a means for direct high-resolution imaging of lipid-phase systems.