Abstract: An apparatus for classifying a liquid patient sample includes at least one sample container having a quantity of a sample that is aggressively acted upon so as to create a flow field. A measurement mechanism includes at least one low angle light emitter aligned with a measurement window of the at least one sample container and a detector oppositely disposed relative to the measurement window. Measurement of the scattered light detects particle characteristics of a moving flow field from the sample to determine, for example, the amount of agglutination of the sample so as to perform blood typing or other classifications without spatial separation.

Abstract: An apparatus for classifying a liquid patient sample includes at least one sample container having a quantity of a sample that is aggressively acted upon so as to create a flow field. A measurement mechanism includes at least one low angle light emitter aligned with a measurement window of the at leas tone sample container and a detector oppositely disposed relative to the measurement window. Measurement of the scattered light detects particle characteristics of a moving flow field from the sample to determine, for example, the amount of agglutination of the sample so as to perform blood typing or other classifications without spatial separation.

Abstract: Hydrolyzable substrates for acid and alkaline phosphatases comprise blocked dye moieties which, when cleaved from the substrate during hydrolysis, provide fluorescent dyes having maximum absorptions above about 530 nm and maximum fluorescent emissions at least about 580 nm. The dyes are blocked prior to hydrolysis with a phosphono or thioxophosphono group or a salt thereof. These substrates can be used in analytical determinations of acid or alkaline phosphatase, or in competitive binding reactions to determine immunologically reactive substances.

Abstract: Novel chromogenic derivatives of 1,2-bis-(o-aminoaryloxy)ethane-N,N,N',N'-tetraacetic acid are useful for the determination of calcium ions in both solution and dry assays. These compounds comprise a dye moiety which is directly conjugated to the acetic acid substituted-nitrogen atom and which enables the compounds to exhibit maximum absorbance at a wavelength generally greater than 400 nm before complexation. When the compounds are complexed with calcium ions, the absorbance shifts to a shorter wavelength.

Abstract: Vesicles comprising a matrix of lipid membranes prepared from lipid materials are useful in biomedical studies and immunoassays. A labeled species is encapsulated within the vesicles and released when the vesicles are lysed with a surface active agent. The outer surface of the vesicles is essentially free of the labeled species. Immunoassays can be carried out in solution or with a dry analytical element.

Abstract: A heterogeneous, competitive binding immunoassay for either phenytoin or phenobarbital is conducted with a labeled conjugate comprising a derivative of hydantoin and a label. The hydantoin derivative is 5-ethyl,5-phenyl hydantoin and it is linked to the label (e.g. an enzyme) with a linkage derived from an aliphatic monocarboxylic acid. The immunoassay can be carried out either in solution or with a dry analytical element.

Abstract: A heterogeneous, competitive binding immunoassay is conducted with a dry analytical element. The immunoassay is useful for determining a ligand (e.g. a therapeutic drug) and includes contacting a finite area of the element spreading layer with a sample of a liquid in the presence of a labeled ligand analog and an immobilized receptor. An immobilized ligand-receptor complex is formed within the finite area. Simultaneously, the uncomplexed ligand migrates horizontally away from the immobilized complex which remains in the center of the finite area. At least five seconds after the completion of the contacting, the amount of immobilized complex is measured in the center of the finite area.

Abstract: There are described stabilized fluorescent labels comprising rare earth chelate incorporated in polymeric beads derived from a latex. Labeled reactive proteinaceous species such as labeled immunoreagents comprising the stabilized fluorescent labels having portein adsorbed or covalently bonded thereto are also described.

Abstract: There are described stabilized fluorescent labels comprising rare earth chelate incorporated in polymeric beads derived from a latex. Labeled reactive proteinaceous species such as labeled immunoreagents comprising the stabilized fluorescent labels having protein absorbed or covalently bonded thereto are also described.

Abstract: 1-(P-Benzenediazonium)-ethylenediaminetetraacetic acid is described. This material is a chelating agent which forms stable complexes with the ions of heavy metals including those having radioactive properties and also reacts readily and rapidly with biological molecules. The compound is a versatile reactive agent useful in introducing metal ions into biological molecules.

Abstract: Chelating agents having in addition to their metal sequestering groups a functional group capable of reacting with bio-organic molecules are disclosed, in particular, substituted ethylenedinitrilotetraacetic acids such as 1-p-nitrophenylethylenedinitrilotetraacetic acid, 1-p-aminophenylethylenedinitrilotetraacetic acid and their derivatives are disclosed. These compounds are effective chelating agents and in addition are useful in the perturbed angular correlation method of studying molecular behavior.