Abstract: A purified peptide mimotope which is capable of binding specifically to an antibody specific to estradiol. Also disclosed is an immunoassay test device for the detection in a sample of estradiol, the immunoassay test device comprising a peptide mimotope of estradiol, and an antibody capable of binding specifically to the peptide mimotope to generate a detectable signal.

Abstract: A purified peptide mimotope which is capable of binding specifically to an antibody specific to estradiol. Also disclosed is an immunoassay test device for the detection in a sample of estradiol, the immunoassay test device comprising a peptide mimotope of estradiol, and an antibody capable of binding specifically to the peptide mimotope to generate a detectable signal.

Abstract: Disclosed is a method of detecting the presence of an analyte of interest in a sample, the method comprising the steps of: providing a binding partner reversibly immobilised on a solid support, said binding partner having binding specificity for the analyte; contacting the sample with the solid support; specifically displacing the binding partner from the solid support in response to the presence of the analyte of interest in the sample, said displacement causing a reduction in the mass of material immobilised on the solid support, thereby generating a detectable change in a mass-dependent property of the solid support; and detecting said change. Also disclosed is an assay device for performing the method of the invention.

Abstract: An antibody specific for a target analyte is purified by affinity chromatography on a substrate bearing a low-affinity analogue of the target analyte. The antibody is displaced from the substrate by contact with a second analogue of intermediate affinity, which remains complexed with the antibody. This complex can be used in a conventional assay for the target analyte, which displaces the intermediate-affinity analogue. The complexed antibody is rendered more storage-stable because the second analogue protects the antibody binding reagion.

Abstract: Improved affinity purification media are provided by the use of small specific binding agents, especially Fv antibody fragments or single domain antibody fragments, immobilised on porous carriers having pore sizes in the range 30-1000 angstroms, preferably 30-300 angstroms. Silica is a preferred carrier. The small fragments are able to penetrate the pores and maximise the effective surface area of the carrier, and the microporous silica is sufficiently robust to be used at high pressure, so enabling the speed and/or throughput of a purification procedure to be increased.