Abstract: The invention encompasses an improved, rapid, size-exclusive method for screening for small molecular weight ligands that bind specifically to a protein target, using size-exclusion separation, ultrafiltration, and mass spectrometry.

Abstract: The invention relates to a capillary electrophoresis-based method of screening complex materials for any unidentified affinity ligand that binds to a target of interest. The method subjects a plug of a mixture of the target and a complex material sample, and a separate plug of a known, tight-binding competitive ligand, to capillary electrophoresis under conditions optimized to allow mingling of the two plugs during the capillary electrophoresis run. Preferably, migration of the competitive ligand is tracked.

Abstract: The invention is directed to a high throughput capillary electrophoresis (CE) system, which comprises multiple mobile CE detector modules that are transportable by a programmable fluid-handling arm assembly to fixed samples in microtiter plate wells for analysis. The CE system of the invention is capable of simultaneously automating sample preparation and multiple CE analysis of the sample in a continuous timely process. The CE detector modules of the invention may be equipped with any suitable detection method, such as an ultraviolet (UV) absorbance or a laser-induced fluorescence (LIF) detector.

Abstract: The invention relates to capillary electrophoretic methods for detecting ligands or hit compounds that can bind to a selected target at or above a selected binding strength. The method allows one to rank various ligands based on their relative affinity, i.e., the relative stability of the target/ligand complex during capillary electrophoresis under selected conditions. The method also enables selective detection of strong-to-moderate binding hit compounds, even in the presence of high concentrations of weaker, competitive hit compounds.

Abstract: This invention combines a capillary electrophoresis (CE) technique for screening complex biological samples with mass spectrometry (MS), to provide a streamlined procedure for identifying and characterizing candidate ligands in a complex biological sample that bind at a selected binding strength to a selected target molecule. The method of the invention advantageously identifies and characterizes tight-binding ligands when high concentrations of weak ligands are present in the sample, which may mask lower concentrations of tight-binding ligands in the sample. The method involves interfacing a capillary from a CE instrument with a post-capillary mass spectrometer to provide direct mass analysis of target/ligand complexes that migrate stably through the CE instrument. All weaker-binding ligands will not be detected during the MS analysis because they dissociate from the target early during the CE run, before reaching and entering the mass spectrometer.

Abstract: This invention relates to a competitive-binding, capillary electrophoretic method of detecting new therapeutic regulatory (modulating) and diagnostic compounds in natural samples and other complex biological materials. The present method generally comprises mixing a preselected, detectable target with a sample of complex biological material to produce a first, sample/target mixture capillary electrophoresis apparatus. Subsequently, the first mixture is mixed with a pre-selected, tight-binding competitive ligand (TBCL), prior to produce a second, sample/target/TBCL mixture, for a predetermined optional incubation period sufficient to allow the TBCL to bind a pre-selected percentage of the available target in the absence of any other ligand. An aliquot of the second mixture is subsequently subjected to pre-optimized capillary electrophoresis, during which the migration of the target is monitored.