Abstract: A technique for measuring the degree of an antigen-antibody reaction by preparing a suspension of insoluble microscopic carrier particles of at least one type carrying an antigen, an antibody or a hapten, forming an agglutination promoting or inhibiting reaction system among the insoluble carrier particles based on an antigen-antibody reaction using the suspension and one or more antigen, antibody or hapten, irradiating the solution of the reaction system with laser light and detecting the light scattered from the reaction system at one or more specific angles, detecting a signal indicative of one or more specific frequency bands from the resulting scatter spectrum, and thenceforth calculating the quantity of antigen, antibody or hapten in a specimen on the basis of the detected signal. The intensity spectrum output of filter 11 for frequency band selection is in the form of a square root and is converted into the original intensity spectrum by means of a squaring circuit 12.

Abstract: A method and apparatus for quantitatively determining a degree of agglutination of a suspension of particles or the presence of the agglutination thereof is disclosed, wherein a liquid which contains agglutinated clots, otherwise a substance or substances to be about to agglutinate is made to slowly transfer through a small tube, in course of which agglutinated clots and non-agglutinated particles separate from each other in the liquid, when a degree of agglutination of particles and the concentration of the substance to be tested herewith can be determined quantitatively through the detection of difference in the optical properties of both the accumulation layer of agglutinated clots and the suspension layer of non-agglutinated particles, or the change in the optical properties of either of the above two layers, in particular the suspension layer.

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: The hemolytic method for the kinetic determination of antistreptolysin O antibodies (ASO) in blood samples consists of reacting a first reagent containing a single dose of oxidized SO with the specific antibodies which may be present in the blood sample under examination, allowing the necessary time to pass for the reaction between the oxidized SO and said antibodies to take place, returning the oxidized SO to its reduced state by adding a second reagent, and measuring the rate of hemolysis. The kinetic determination of the ASO titre is obtained by comparing said rate of hemolysis with the rate of hemolysis shown graphically for samples of known ASO titre.

Abstract: A process is presented for conducting fluorescence immunoassays without the use of added labels by utilizing ultraviolet radiation and internal reflection optics to activate fluorescent groups present in the molecules of interest.