Abstract: An immunological assay method, wherein the concentration of a substance to be assayed is calculated from a calibration curve, which is formed in the preparation of a reagent or in the assay of a sample based on parameter(s) determined in the preparation of the reagent, without the need of forming any additional calibration curve each time, is disclosed. By the immunological assay method of the present invention, the concentration of the substance to be assayed can be efficiently and discontinuously determined, when compared with conventional ones. The method of the present invention is particularly suitable for quantitatively determining an antigen or an antibody.

Abstract: Dyed inorganic composite particles having a mean particle diameter of 0.1 to 10.0 micrometers and a particle dispersibility value of at least 80%, each of said particles consisting of at least three layers comprising a core, a dyed layer on the surface of the core and a coated layer on the dyed layer, the core being composed of an inorganic compound, the dyed layer being composed of a dye or a mixture of a dye and an inorganic compound, and the coated layer being water-insoluble and light-pervious and composed of an inorganic compound or a mixture of it with a dye. The particles are useful as a carrier for preparing an immunological diagonostic reagent by binding an immunologically active substance (an antigen and an antibody) to them, particularly an immunological diagnostic reagent for use in a microtiter method, or as a hydrophilic pigment.

Abstract: The present invention provides a vinyl chloride polymer composition comprising an intimate mixture of a first vinyl chloride polymer containing a sulfide linkage in the molecular chain and a second vinyl chloride polymer having a higher molecular weight than the first polymer, and a process for producing a first vinyl chloride polymer for use in the composition, comprising polymerizing vinyl chloride or a mixture of vinyl chloride and an ethylenically unsaturated monomer in the presence of a free radical initiator using as a chain transfer agent a mercapto compound or a disulfide compound. Said vinyl chloride polymer composition has been improved in heat stability and processability.