High-Brightness Fluorophores for Cell Phenotyping

Flow cytometry (FCM) is a laser spectroscopy technique that detects, counts, and sorts thousands of cells per second. For example, FCM enables cell phenotyping by characterizing the population of clusters of differentiation (CD) on cells. Laser-induced fluorescence from fluorophores conjugated with antibodies can identify various CD on cell surfaces. The multiparametric and high throughput capabilities have made FCM a standard technique for research and clinical laboratories to characterize stem cells, cancer cells, nucleic acids, etc.<br/><br/>We have developed a platform technology to produce high-brightness fluorophores (HBFs, NovoLux dye) for use in FCM. Our unique technology allows us to tune the fluorescent brightness of HBFs to desired levels (10X to 1000X brighter than commercial dyes). We can use any organic dye molecules to formulate HBFs to emit at desired fluorescent wavelengths. To date, we have developed Four types of HBFs: NovoLux 405, NovoLux 488, NovoLux 560 and NovoLux 640. The molar extinction coefficient (e) of NovoLux dyes can be as high as 10⁷to 10¹⁰ M^-1 cm^-1 [1-3]. It is several orders of magnitude higher than any existing dye (e for FITC is 7.8x10⁴ M^-1 cm^-1, for Rhodamine B is 7.5x10⁴M^-1 cm^-1, for Cy5.5 is 2x10⁵).<br/><br/>This unique property allows our HBFs to increase the staining index of some rare biomarkers (CD127, CD 19, etc.) in FCM measurements. The spectral properties, fluorescent brightness tunability, and application of NovoLux dyes in FCM will be presented in the meeting.