In Situ Imaging of Metals in Cells and Tissues

An overview of some of the latest efforts made at tracing metal imaging and offering a perspective of this rapidly evolving research field is presented. A number of significant microanalytical techniques are available for the in situ detection of trace metals in cells and tissues. Each offers specific advantages and disadvantages depending on the task to be performed. Synchrotron and focused ion-beam microscopic techniques offer the best combination of sensitivity and spatial resolution. It has been observed that fluorescent dyes offer significantly greater optical sensitivity and have the potential for observing biological processes at the single-molecule level as compared with chromogenic histochemical stains. These indicators have the potential to passively diffuse across cell membranes and are better suited for the noninvasive imaging of cation fluxes in living cells due to their smaller molecular size.