Abstract: The invention relates to an assay for determining an analyte in a fluid sample. Three receptors are used, with formation of a quaternary or four member complex. One of the receptors is bound to a solid phase, and binds to complexes of another receptor and the analyte. A third receptor is labelled, and it, too, binds analyte. The invention also involves the use of a displacement solution to wash fluid sample from solid phase after the first portion of the quaternary complex forms, i.e., prior to binding with the labelled receptor.

Abstract: An apparatus for determining an analyte in a sample, as well as a method for carrying this out, are disclosed. The apparatus utilizes a first zone containing a labeled substance, and a second zone which permits separation of a mobile detectable moiety from unreacted reaction component. Detectable moiety is the product of reaction between reaction component and labeled substance.

Abstract: A process for the detection of substances with hydrolase activity in a sample by mixing the sample with a hydrolase substrate and an oxidizing agent, and the evaluating the resultant color intensity, wherein, as hydrolase substrate, there is used at least one compound of the formula ##STR1## in which R.sup.1 is hydrogen or an alkoxy radical,R.sup.2 is hydrogen or halogen, an amino group or an alkoxy or aralkoxy radical,R.sup.3, R.sup.4, R.sup.5 and R.sup.6, which can be the same or different, are hydrogen, halogen, carboxyl, a carbamoyl group, sulpho, an amino groups alkyl, an alkoxy radical, aralkoxy, alkylcarbonyl or alkoxycarbonyl, andX is a glycosyl, phosphate or acyl residue.Optionally R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, and R.sup.5 and R.sup.6 can be joined to form a ring system. At least one of R.sup.1 and R.sup.2 must be hydrogen and at least one of R.sup.1, R.sup.2 and R.sup.3 must not be hydrogen. Compounds in which X is .beta.-galactosyl are new.

Abstract: This invention relates to apparatus useful in determining a component or components of a test sample, as well as methods using these apparatus. Of particular interest are apparatus and methods which involve formation and determination of quarternary complexes.

Abstract: The invention relates to a heterogeneous immunoassay which is carried out using a multizoned test device. In particular, the invention involves the use of an inhibitor of a label which is used in the assay. The label which may be an enzyme, is attached to a receptor such as an antibody. The inhibitor is not acted upon by the label, but must be removed in order for a signal to be produced. Also described are test strips which can be used for the assay.

Abstract: The invention involves an apparatus useful in analysis of liquid samples. At least 3 zones are provided which contain reactants which interact with the analyte and each other, leading to the detection reaction. The apparatus also has a fluid application means for reception of a liquid, and a waste zone, which absorbs excess liquid after the detection reaction has taken place. The fluid application means and waste zone are positioned at opposite ends of the apparatus.

Abstract: This invention relates to apparatus useful in determining a component or components of a test sample, as well as methods using these apparatus. Of particular interest are apparatus and methods which involve formation and determination of quarternary complexes.