An analyte is determined quantitatively by an agglutination assay by use of a method which includes the use of at least two analyte standards having different analyte concentrations; an analyte supported on a particulate support; specific binder for the analyte and buffered diluent for making serial dilutions of an analyte sample. The assay is preferably conducted on a test card which includes a sample portion and a standard portion, with the sample portion having a series of separated marked dilution areas for receiving dilutions of an analyte sample and the standard portion including separated marked standard areas for receiving analyte standard of different analyte concentration. By addition of binder and particles sensitized with analyte to the serial dilutions and standards, analyte can be determined quantitatively by multiplying the lowest standard concentration at which there is no visible agglutination by the highest reciprocal dilution of test sample which similarly shows no visible agglutination.

An improved specimen test slide having a front panel and a rear panel. The front panel has one or more openings. Sheet means carrying a test reagent underlie each of these openings for reception of a specimen. A hinged cover overlies the openings. The rear panel has flap means opposite said openings which is pivotable to expose the underside of the sheet to permit application of a developing solution. The underside of the sheet which faces the rear panel also has a control area positioned on a portion thereof at some distance from the portions of the sheet underlying the openings of the front panel. The control area contains positive and negative monitors.

An assay for an immunologically active substance (B) in a biologically derived test sample comprising using an immuno-active membrane of a hydrophobic polymer sheet having numerous hydrophilic spots, on which a prefixed amount of an immuno-active substance (A) or (B) has been immobilized, and a coloring-membrane having numerous spots which contain a color-producing reagent being capable of developing color by the catalytic effect of an enzyme at the corresponding positions to those of the immuno-active membrane, and making contact the immuno-active membrane with said test sample in the presence of an enzyme-labeled immuno-active substance (A') or (B') and a substrate for reacting the substance (A), substance (B) and enzyme-labeled substance (A') or (B') competitively or non-competitively, and superposing the coloring-membrane of on the immuno-active membrane, followed by colorimetrically measuring the resulting color and thereby determining the amount of the substance (B) in the test sample.

A chemical test kit for determining the presence of occult blood in a stool specimen is disclosed which includes an improved monitor system for verifying the effectiveness of the chemicals used in the test. A method of testing for occult blood is also disclosed which method includes verifying the effectiveness of the chemicals utilized in the test.

An improved chromogen-reagent test system for a slide, test kit or the like has particular utility in the testing of fecal specimens for occult blood. The chromogen-reagent system may include the use of colorless guaiac which, in the presence of a developing solution and a catalyst, is oxidized to yield a predetermined color such as blue. Hydrogen peroxide is used as the developing solution and hemoglobin in the fecal specimen functions as the catalyst. The chromogen-reagent test system includes an indicator area for determining if the guaiac and the developing solution are functioning properly, i.e., the test system of the present invention verifies that the guaiac has not lost its activity nor been improperly catalyzed and that the hydrogen peroxide has not lost its activity. The indicator area includes a catalyst which has a greater stability than blood, in respect to adverse environmental conditions, such that a determination can be made if the reagents are functioning properly.