Combining two powerful technologies - liquid chromatography and bioassays results in analytical methodologies which are characterised by high selectivity and sensitivity. In contrast to microtitre-type bioassays, biochemical reactions proceed in a closed, continuous-flow reaction detection system coupled directly to the outlet of the chromatographic separation column. The interaction of substances eluting from the separation column with molecular targets such as antibodies or receptors is monitored directly overcoming tedious fraction collection and manual operations required to prepare the functions for batch immunoassays. important application areas are bioanalysis and drug discovery.