Diagnostic Reagents, Inc.

Adeza Biomedical Corporation

Yuh-geng Tsay

Cheng-I Lin

Eric K Gustafson

John Lee

The present invention concerns a method of enzymatically determining the pH of a specimen (e.g., a solution or a biological fluid) and a kit for conducting the method. The present method involves mixing (1) a specimen with (2) an enzyme and (3) one or more substrates for the enzyme in a buffered solution having a pH effective to provide a direct proportional relationship between the activity of the enzyme and the pH of the specimen; determining the activity of the enzyme; and correlating the activity of the enzyme to the pH of the specimen. Each of the sample, the enzyme, the substrate and the buffered solution is present in an amount effective to provide the direct proportional relationship between the activity of the enzyme and the pH of the specimen. The present kit contains an enzyme, one or more substrates for the enzyme present in an amount effective to determine the enzyme activity, and a buffered solution having a pH effective to provide a direct proportional relationship between the activity of the enzyme and the pH of the specimen. The present invention is particularly applicable to detecting adulteration of a urine specimen.

Method and kit for enzymatically determining the pH of a specimen

A reflective biograting consists of an optically flat layer of a transparent composition such as silicon dioxide having a first and second surface, alternating zones of active and inactive binding reagent on the first surface, and a reflective metal layer having a thickness of at least above 1000 .ANG.. The reflective metal layer can be supported on an optically flat surface of a wafer, and the reflective metal can be aluminum, silver, gold, chromium, nickel, titanium or platinum coating on a polished wafer. Preferably, the silicon dioxide layer is formed either by direct sputtering of silicon dioxide or by coating an alkali metal silicate solution on the surface of the reflective metal, optionally containing an aminoalkylsilane and a water-soluble hydroxylated polymer such as a dextran. Alternatively, the reflective support comprises one or more reflective layer units, each reflective layer unit comprising an optically flat layer of silicon, and preferably polysilicon, on a layer of silicon dioxide. Each layer of silicon has a thickness within the range of from 150 to 750 .ANG., from 850 to 1300 .ANG., or from 1700 to 2150 .ANG., and preferably within the range of from 200 to 600 .ANG.. Each layer of silicon dioxide has a thickness within the range of from 800 to 1200 .ANG.. The reflective support is supported on the substantially flat surface of an insoluble support.

Highly reflective biogratings

Novel derivatives of phencyclidine are provided as precursors for conjugating to antigenic proteins for the preparation of antibodies which bind to phencyclidine or conjugation to enzymes for use as reagents in immunoassays. The combination of the antibodies and enzyme conjugates provide a sensitive and rapid assay for phencyclidine.

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Los Altos Hills, CA, United States of America

Yuh-geng Tsay