Is it better to measure cell cytotoxicity using absorbance or fluorescence?
alamarBlue® reduction is regularly measured using absorbance, which gives good levels of accuracy for most experiments, and is particularly easy to use. It is generally the case, however, that more sensitive readings can be obtained when fluorescence is used, especially when attempting to measure very small changes in reduction. This is principally because there is little interference from unreduced alamarBlue® on the spectra of reduced alamarBlue® when measured by fluorescence (Figure 2a). When measuring absorption there can be considerable overlap of the oxidized and reduced forms of alamarBlue® (Figure 2b).
