Ventana Medical Systems, Inc.

Michael J DeGroff

Phillip C Miller

Pamela S Vandivort

Michael J Gizinski

James A Rybski

Anthony L Hartman

Brian J McGraw

Thomas P Krawzak

David W Nunnery

The present invention provides an improved method for staining slides using immunochemical reagents. The method comprises the following steps. The assay region of a slide (the region containing the tissue section)is washed with an improved rinsing solution comprising water and a detergent. An evaporation inhibitor liquid is applied to the slide to cover the assay region. For antigens requiring unmasking, the tissue section is combined with an improved, stabilized proteolytic enzyme solution. The slide is rinsed, and the evaporation inhibitor liquid is reapplied to the slide. A primary antibody in an improved diluent containing globulins from the same species as a second antibody is combined with the tissue section for a time sufficient for substantially complete antibody binding. The slide is rinsed, and the evaporation inhibitor liquid is reapplied. A labeled second antibody in the improved diluent is combined with the tissue section for a time sufficient for substantially complete antibody binding. The slide is rinsed, and the evaporation inhibitor liquid is reapplied to the slide. Color development reagents, including a stabilized peroxidase chromophore formulation, are combined with the tissue section for a time sufficient for color development. The stabilized peroxidase chromophore formulation consists essentially of a peroxidase chromophore, at a concentration in the working range of the enzyme, an acidic buffer, a reducing agent, and a glycol. Preferred chromophores include 3,3'-diaminobenzidine and tetrahydrochloride (DAB) and 3-amino-9-ethylcarbazole (AEC). After color development, the tissue section is washed and is then ready for analysis.

Immunohistochemical staining method and reagents therefor

A dispenser which can deliver precise small amounts of a liquid is disclosed. The dispenser is particularly suited to applying reagents in a biological test such as an immunoassay. It includes a reservoir chamber linked to a dispense chamber via a check valve, the two chambers preferably being in the form of syringes. An outlet line leading from the dispense chamber to a nozzle includes a delay check valve (preferably a ball inside a cylindrical chamber) which allows continuous outward flow, but shuts off flow in the reverse direction after allowing a predetermined volume to pass. The process of refilling the dispense chamber from the reservoir chamber creates reverse flow in the nozzle and causes a hanging drop of liquid at the tip of the nozzle to be withdrawn.

Liquid dispenser

The present invention provides an immunohistochemical staining method using improved reagents. In one aspect, the method uses an evaporation inhibitor liquid to prevent evaporation of reagents applied to an assay region of a slide.

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Tucson, AZ, United States of America

Michael J DeGroff