A rapid fluorescent screening method for cellular sensitivity to anti-cancer compound

The tetrazolium salts (MTT, XTT, MTS, WST) based colorimetric assay or resazurin based fluorimetric assay are currently typical methods for cell sensitivity determination to anticancer compounds. We presented here a new rapid method for this purpose. This method uses a fluorescent dye named DCFH-DA which is previously taken as a intracellular probe for measurement of H2O2 levels within a cell. The application basis for this method lies in two facts: the membrane permeable feature of the final metabolite of DCFH-DA inside a cell, and the linearity relationship between cell number and H2O2 level. The results showed that there was a perfect association between cell number and fluorescent intensity determined by the DCFH-DA method, no matter whether using resuspended or adherent cells, and further 50% concentration of inhibition (IC50) comparison between data obtained by DCFH-DA method or MTT method using a positive known anticancer compound Baicalin showed that there were no significant differences in cellular sensitivity determination to compound Baicalin though there existed a relatively higher coefficient of variation of IC50 by the DCFH-DA method than that by the MTT method. Thus our data indicate that DCFH-DA might not only be a fine reagent for determination of H2O2 levels in cells but also an ideal fluorescent dye for cellular sensitivity test of anti-cancer compounds, and may be suitable for primary high-throughput drugs screening.