Abstract: A method of detecting protease activity in a sample. The method includes contacting the sample with a composition containing (i) a dispersion of gold nanoparticles, whose surface is coated with a gelatin; and (ii) CaCl2. A color change of the composition, a turbidity change of the composition, or both, upon the contacting of the sample with the composition, indicates the presence of protease activity in the sample. A kit adapted for performing the method. The kit includes (i) a vial containing a composition comprising CaCl2 and a dispersion of gold nanoparticles whose surface is coated with a gelatin; (ii) a cap configured for attachment to the vial, comprising a rubber septum; and (iii) a sampling device configured for collecting a fluid from a wound.

Abstract: The present invention is drawn toward a lateral-flow, colorimetric, gelatinase assay including a sample pad, a reagent pad, a membrane, and an absorbent pad, in that order, wherein the reagent pad has therein a dried form of gelatin-coated nanoparticles in a salt and sugar matrix, and wherein the membrane portion has a test stripe and a control stripe, such that the test stripe is a solution of electrolyte evaporated into a layer, and the control stripe is a solution of anti-gelatin antibody evaporated into a layer. The present invention is also drawn toward a method of detecting one or more gelatinases in a sample fluid using the assay, and methods of determining treatment for wound healing, cancer, ocular rosacea, periodontal disease and equine arthritis using the assay.

Abstract: The present invention is drawn toward a lateral-flow, colorimetric, gelatinase assay including a sample pad, a reagent pad, a membrane, and an absorbent pad, in that order, wherein the reagent pad has therein a dried form of gelatin-coated nanoparticles in a salt and sugar matrix, and wherein the membrane portion has a test stripe and a control stripe, such that the test stripe is a solution of electrolyte evaporated into a layer, and the control stripe is a solution of anti-gelatin antibody evaporated into a layer. The present invention is also drawn toward a method of detecting one or more gelatinases in a sample fluid using the assay, and methods of determining treatment for wound healing, cancer, ocular rosacea, periodontal disease and equine arthritis using the assay.

Abstract: The change between a dispersed state and a flocculated state of a colloidal agent (e.g. Congo Rubin, colloidal gold) is used to provide sensitive visual detection and optionally assay of enzyme in a sample. The test cell includes a substrate for the enzyme, and, depending on the action of the enzyme, polymer which protects the colloid from electrolyte-induced flocculation is either formed or destroyed by the test reaction. In a test for a hydrolytic enzyme (e.g. a protease) the colloid loses protection and flocculates. In a test for a polymer-forming enzyme, the colloid gains protection and is prevented from flocculating by added electrolyte, or alternatively, depending on the polymer's behavior, becomes more sensitive to the flocculating action of the added electrolyte. The measurement may be quantitated using an instrumental monitor. The test uses a natural substrate for the enzyme to be assayed (e.g., gelatin for the gelatinase class of enzymes) and may achieve rapid speed.

Abstract: A solid-phase immunoassay support is provided by treating a test tube liner such as a preformed soft gelatin capsule half with a coupling solution comprising a fixative, a bifunctional coupling agent and a bioactive protein which selectively reacts with the substance which is the subject of the immunoassay. The support is particularly applicable to the radioimmunoassay (RIA) technique for determining the presence and concentration of minute amounts of protein antigens in biological fluid samples and can be readily inserted in an appropriately sized test-tube for easy and quick assays.