Monitoring Cellular Performance
“Mitochondria were long neglected as a tool for cell-based assays,” says Steve Chomicz, vp of sales and marketing at Seahorse Bioscience. Although their central roles in cancer and many other pathological processes have been long recognized, the tools for studying mitochondrial function have hardly changed since the 1930s.
According to Chomicz, many cell-based assays measure features such as cell permeability, and in doing so miss the vital contribution of mitochondrial health to cell function. “We perform the equivalent of a stress test on our cells that reveals dysfunctional respiratory capacity,” he explains.
It is now possible to monitor myocytes grown under conditions that mimic a lean or obese model in order to develop a realistic cell-based assay for studying drugs that may affect metabolism. This includes the measurement of cellular respiration, revealing important cellular responses not detectable with other viability assays. An important feature of the XF platform is its noninvasive, physiologic measurement for primary or cultured cells, allowing the cells to be recycled for other purposes.
The Future of Cell-Based Assays
According to Andrew Niles, Ph.D., and his colleagues at Promega, there is a tendency within the industry to move to bioluminescent assays and away from traditional absorbance and fluorescence chemistries.
Bioluminescent proteins have a number of advantages over conventional organic fluorescent dyes. They are highly restricted within the kingdom of living organisms, are much more sensitive, and are rarely subject to quenching or interference through autofluorescence. However, new ways of examining cellular response are on the horizon, and being label-free is especially tantalizing.