Abstract: The present invention provides various methods for detecting errors in a blood analysis system. The system includes a blood analyzer and a molded plastic rotor with a series of chambers and capillary channels through which blood is processed and distributed to cuvettes which contain lyophilized reagents. The rotor is placed in the analyzer which spins the rotor, and an optical system reads the cuvettes as light is flashed through the cuvettes.

Abstract: A new and improved test device and method of determining the presence or concentration of a predetermined analyte, such as glucose, cholesterol or occult blood, in a test sample are disclosed. The test device includes a test pad comprising a suitable carrier matrix incorporating an indicator reagent composition capable of interacting with the predetermined analyte to produce a detectable or measurable response.

Abstract: The present invention is directed to the elimination of ascorbic acid interference in assay systems, particularly assay systems based upon oxidase-peroxidase coupled reactions. When ascorbic acid is present in a sample, it can act as a reductant thereby interfering with an assay's reagent system. The present invention eliminates this inteference by quickly oxidizing any ascorbate thereby preventing ascorbate from acting as an unwanted reductant. The ascorbate is oxidized using a dual oxidant system comprising a water soluble polymer bound to Cu.sup.+2 and an organic or inorganic oxidant such as chromate, peroxide, or a N-halo derivative. This invention is surprisingly selective and generally will not itself interfere with the assay's reagent system. Furthermore, the present invention is so fast and efficient that it can be incorporated into a convenient format, such as a conventional "dip-and-read" reagent test strip system.

Abstract: A method and test means for determining a specific binding substance, such as an antigen or hapten, in a liquid sample wherein a solid, nonspecific adsorbent is contacted, preferably in sequence, with the sample and a labeled form of a binding partner for the substance to be determined, such as a labeled antibody. The amount of label which becomes associated with the adsorbent by binding of the labeled binding partner to the adsorbed substance to be determined, i.e., in a sandwich fashion, is a function of the amount of the substance to be determined in the liquid sample. Preferably, the adsorbent is an ion exchange material, and the assay steps are carried out under pH conditions between the isoelectric points (pI values) of the substance to be determined and the labeled binding partner. The method and test means are particularly suited for the detection of hepatitis B surface (HB.sub.s) antigen, especially where the label is a radioactive material and a column format is employed.

Abstract: A method for the combined radioimmunoassay for the hormones triiodothyronine (T-3) and thyroxine (T-4) in serum or plasma, wherein the radiolabeled T-3 and T-4 reagents are T-3 and T-4 labeled with the same radioisotope. The hormones are extracted from the serum or plasma sample and separated from their binding proteins by adsorption to a crosslinked dextran gel at a highly alkaline pH. After washing away the dissociated proteins, a predetermined limiting amount of T-3 antibody is incubated with the gel and thereafter radiolabeled T-3 which has become extracted from the gel by antibody binding is washed away. Excess T-3 antibody and a predetermined limiting amount of T-4 antibody are then incubated with the gel and radiolabeled T-3 and T-4 which has become extracted from the gel by antibody binding are thereafter washed away.

Abstract: A method and test means for determining a specific binding substance, such as an antigen or hapten, in a liquid sample wherein a solid, nonspecific adsorbent is contacted, preferably in sequence, with the sample and a labeled form of a binding partner for the substance to be determined, such as a labeled antibody. The amount of label which becomes associated with the adsorbent by binding of the labeled binding partner to the adsorbed substance to be determined, i.e., in a sandwich fashion, is a function of the amount of the substance to be determined in the liquid sample. Preferably, the adsorbent is an ion exchange material, and the assay steps are carried out under pH conditions between the isoelectric points (pI values) of the substance to be determined and the labeled binding partner. The method and test means are particularly suited for the detection of hepatitis B surface (HB.sub.s) antigen, especially where the label is a radioactive material and a column format is employed.