Determining total protein concentration is an accepted means of comparing and standardizing biological samples. The utility of protein concentration assessment extends to high-throughput screening platforms including proteomic and genomic applications. Ideally, the protein concentration determination should also be amenable to high throughput. Most protein determination assays use absorbance measurement detection which is difficult to minimize for higher throughput.
Previously, it has been reported that colorimetric assays, including the bicinchoninic acid (BCA) protein assay, can be performed in white plates using fluorescence detection. The method exploits the inherent fluorescence of white plates. In presence of an absorbing solution, the inherent fluorescence is quenched and the decrease in fluorescent signal can be used to measure colorimetric assays. This principle was employed to miniaturize the BCA protein quantification assay down to 384- and 1536- well plates.