FLUORESCENCE CORRELATION SPECTROSCOPY (FCS) - A HIGHLY SENSITIVE METHOD TO ANALYZE DRUG TARGET INTERACTIONS/

Fluorescence Correlation Spectroscopy (FCS), a new analytical technolo gy, allows binding properties to be determined very accurately in biol ogical assays at the level of single molecules. At concentrations of g reater than or equal to 10(-12) M, binding constants, on/off-rates, an d even reaction/enzyme kinetics can be determined in real-time, and in sample volumes as low as 10(-9) mu l. The FCS technology can be appli ed to study molecular and cellular interactions in homogeneous assays. Assay times in the range of seconds in combination with nanoliter sam ple volumes allow FCS to be used for high throughput screening to iden tify new pharmaceutical lead structures or new pharmacological targets . FCS is fully compatible with standard microtiter plate formats. Howe ver, for high throughput screening, specially designed sample carriers containing many thousand sub-microliter sample wells may be used in c ombination with a nanopipetting and sample retrieval system.