Abstract: A process for the preparation of an enzymatically active formulation embedded in silica gel, wherein an aqueous mixture of an enzymatically active formulation and a dissolved alkali metal silicate and/or ammonium silicate is suspended in an organic, water-immiscible fluid and then converted to a water-insoluble gel.

Abstract: An improved immunoassay technique for determining the presence of estriol in human sera comprises adding preselected amounts of a non-ionic detergent and a surface active agent to the assay medium to lessen inaccuracies resulting from variable serum protein concentrations in the sample.

Abstract: A method and reagent kit means are provided for assay of a selected hapten in an aliquot of body fluid containing lipid. The method comprises the steps of constituting the aliquot in a mixture with surfactant and incubating the mixture to solubilize the same. The content of hapten in the incubated mixture is taken up selectively by hapten-specific antibody and read by hapten non-lipid conjugate tracer assay.

Abstract: Vitamin B.sub.12 (cobalamin) and/or folate (folic acid) assay techniques can be simplified, by eliminating the step of heating or boiling the to-be-tested sample prior to its assay. This is accomplished by utilizing compositions and procedures:(1) which substantially completely liberate all vitamin B.sub.12 and/or folate from endogenous binding protein without heating or boiling;(2) which substantially completely destroy all endogenous binding protein which is present in the to-be-assayed sample, and which may bind natural and radioactive vitamin B.sub.12 or folate both due to its liberation from vitamin B.sub.12 or folate in the original sample or due to its unbound presence in the original sample;(3) which substantially completely inhibit or block any undestroyed endogenous binding protein; and(4) which substantially completely inhibit or destroy any intrinsic factor-blocking antibodies which may be present in the to-be-assayed sample.

Abstract: Radioimunoassay methods for determining the concentration of fibrinopeptide A in plasma, anticoagulation reagents for use in such methods and package test kits containing the reagents for use in such methods are provided.

Abstract: Process for the preparation of test reagents comprising antigens or antibodies adsorbed on a surface, for example, the surface of synthetic or natural polymer particles in which the test material to be adsorbed is dissolved in a solvent in contact with the adsorbing surface and precipitated by the addition of a liquid which is miscible with the solvent, but does not dissolve the test material.

Abstract: Nitrobenzofurazan derivatives having the formula ##STR1## are provided wherein R.sub.1 and R.sub.2 each is hydrogen, lower alkyl or phenyl-lower alkyl; R.sub.3 is hydrogen, hydroxy or lower alkyl; R.sub.4 is hydrogen or lower alkyl; m is 2 or 3; and n is 0, 1 or 2; these compounds are useful analytical tools.

Abstract: The sensitivity of hemagglutination inhibition tests is improved by introducing a determined amount of lyophilized antigen or antibody into serological tubes in the absence of the indicator component. The test fluid to be analyzed is incubated solely in the presence of its binding partner in a liquid phase. After completion of the binding reaction (about 5 hours but extendable to 18 hours), the sensitized indicator solid phase, usually consisting of sensitized red blood cells, is added. By this process a 10 to 20 fold increase in sensitivity of the hemagglutination inhibition test is routinely achieved.

Abstract: A system for the detection of a biological analyte of interest is disclosed which comprises a microencapsulated fluorescer material which has been conjugated to an immunological specie specific to the biological analyte of interest, a means of disrupting the capsule containing the fluorescer and an energy source other than electro-magnetic radiation which is capable of activating the fluorescer.

Abstract: A method for the quantitative determination of renin activity in blood utilizing the measurement of Angiotensin I by treating the blood with ethylenediaminetetraacetic acid (EDTA) and the plasma with phenylmethyl sulfonylfluoride (PMSF) at a preferred pH to ascertain the full range of concentration where PMSF is effective for accurate and quick determination.Also, a method for the quantitative determination of renin activity in blood utilizing the measurement of Angiotensin I by incubating the samples after antibody addition at room temperature (23.degree. to 30.degree. C.) for 1 to 2 hours and separating the free from the antibody bound species with polyethylene glycol after having treated the blood with ethylenediaminetetraacetic acid (EDTA) and the plasma with phenylmethyl sulfonylfluoride (PMSF) at a preferred pH.