Fluorescent indicators have enabled the investigation of changes in intracellular free Ca2+ concentrations. Although they are the undisputed, most sensitive tools for this purpose, some problems are still associated with the most popular Ca2+ indicators Fura 2, Fluo 3 and Indo 1. Furthermore, the application of these indicators is limited, with respect to the range of Ca2+ concentration as well as the location of Ca2+. Fluka now offers new calcium indicators that overcome these traditional problems or limitations: high calcium, near membrane, and leakage resistant.
