Development of homogeneous binding assays based on fluorescence resonance energy transfer between quantum dots and Alexa Fluor fluorophores

ANYL 343

Theo T Nikiforov, theo.nikiforov@invitrogen.com, Corporate Research laboratory, Invitrogen Corporation, 5781 Van Allen Way, Carlsbad, CA 92008 and Joseph M Beechem, Corporate Research laboratory, Invitrogen Corp, 5781 Van Allen Way, Carlsbad, CA 92008.
We have systematically explored the fluorescence resonance energy transfer (FRET) between commercially available quantum dots and Alexa Fluor fluorophores. A variety of covalent conjugates of quantum dots with biologically important molecules (small molecule haptens, proteins, nucleic acids) were prepared and used in the development of FRET based assays together with Alexa Fluor labeled complementary binding partner molecules such as antibodies, proteins and nucleic acids. High efficiencies of resonance energy transfer were observed, and the availability of a variety of quantum dots with different emission wavelengths and a wide choice of Alexa Fluor fluorophores allows the transfer to be further optimized. Experiments were performed to establish that the observed effects were indeed a consequence of energy transfer between the quantum dots (donors) and the Alexa Fluor fluorophores (acceptors). Based on the results, homogeneous immunoassays and nucleic acid hybridization assays were developed. The results from these assays will be presented.