Rapid Critical Micelle Concentration (CMC) Determination Using Fluorescence Polarization

This application note describes the rapid semi-automated determination of CMC values for surfactants in 384-well microplates using fluorescence polarization. 

These data demonstrate that the use of DAF fluorescence polarization as a means to determine the CMC values for surfactants is not only easy and accurate, but that the method can also be easily scaled for large sample numbers. Unlike fluorescence intensity, fluorescence polarization uses a ratio of two measurements on each well, correcting for differences in intensity brought about by experimental conditions, such as pH, temperature, and surfactant concentration. The Synergy Neo reader is a high throughput reader specifically designed for the measurement of large numbers of samples. 

The reader uses modular optic cubes to measure numerous read modalities, which include UV-Vis absorbance, luminescence, fluorescence intensity, time resolved fluorescence, HTRF®, AlphaScreen®, and fluorescence polarization. In regards to fluorescence polarization, the reader is capable of simultaneously determining parallel and perpendicular measurements. Gen5™ software (BioTek instruments) not only controls reader function, but also is capable of automatically performing the 4-parameter logistic fit and calculating CMC values.