Exploiting the liberation of Zn²+ to measure cell viability

Zn(2+) ions are a critical component of cellular machinery. The ion is required for the function of many cell components crucial to survival, such as transcription factors, protein synthetic machinery, metabolic enzymes, hormone packaging, among other roles. In stark contrast to the cells' necessity for a sufficient Zn(2+) supply, an excess of free Zn(2+) is a situation that results in acute toxicity. Under normal conditions, free Zn(2+) levels in the cell are extremely low; whereas estimates of free Zn(2+) are in the subpicomolar range. In this way, the detection of elevated intracellular Zn(2+) can be exploited as a highly sensitive and specific signal to indicate neuronal dysfunction. We have shown that the relationship between intracellular Zn(2+) accumulation and the development of cellular injury/death to be ubiquitous among each of five tissue types tested; demonstrating the broad application and utility of the present technique.