Abstract: A self-contained system uses light reflectivity to examine intensity of a dyed spot on a device membrane surrounded by background area to discern information about the specimen that produced the spot. In a preferred embodiment, a master clock alternatively drives one LED focussed upon the spot center, and then drives two LEDS focused on the background area. Light reflected from the spot and background is detected by preferably two photodetectors (“PDs”) spaced-apart a multiple of 90° azimuthal.

Abstract: A self-contained system uses light reflectivity to examine intensity of a dyed spot on a device membrane surrounded by background area to discern information about the specimen that produced the spot. In a preferred embodiment, a master clock alternatively drives one LED focussed upon the spot center, and then drives two LEDS focused on the background area. Light reflected from the spot and background is detected by preferably two photodetectors (“PDs”) spaced-apart a multiple of 90° azimuthal, a configuration discovered to minimize the effects of uneven membrane topography upon light intensity measurements. The PD outputs are average-summed together and are input to a phase lock-in amplifier system that enhances detected signal/noise by measuring signal voltage without producing noise. The lock-in system simultaneously positively and negatively amplifies the average-summed PD outputs, which amplified signal is then switched in synchronism with the LED drive signals.

Abstract: A specimen containing N. lactamica, N. meningitidis, N. gonorrhoeae or B. catarrhalis is incubated simultaneously with a first substrate for beta-galactosidase and a second substrate for gamma-glutamyl aminopeptidase to form reaction products with one or the other Neisseriae which yields a detectible first or second signal distinct from each other depending upon the presence of the enzyme. Signals may comprise distinct colors which emit either in the absence or presence of diazo dye coupler. A third substrate specific for prolyliminopeptidase in N. gonorrhoeae may be added to form a detectible third signal of the same type. The third substrate may be incubated simultaneously with the first two substrates or later. The absence of all of the first three signals is a positive indication that the specimen contains B. catarrhalis. Also, a diagnostic test kit for performing the above tests with or without lectin or antibody for agglutination based upon specific recognition.

Abstract: Am improved device and method for analyte assay in liquid samples, wherein a porous membrane with an immobilized receptor which is capable of directly or indirectly binding to the analyte is separated from a body of absorbent material capable of absorbing the liquid sample by a septum capable of substantially separating the porous membrane from the absorbent body while substantially directing the flow of the liquid sample from the porous membrane to the absorbent body.

Abstract: A lectin is covalently bonded to an immunological conjugate such as an antibody-antigen or its equivalent. Then, the lectin-conjugate is isolated from the reaction product mixture by one of a number of alternative techniques involving one or more of the following types of reaction; (1) reversible reaction of the lectin with an insolubilized sugar to isolate lectin from the remainder of the mixture, (2) reaction of one immunological component (e.g., antibody) bonded to the lectin with an insolubilized corresponding component (e.g., antigen) to separate the antibody components from the remainder of the reaction mixture, and (3) filtration of the reaction components to separate on the basis of product molecular weight, size and/or shape of the components.

Abstract: A lectin is covalently bonded to an immunological conjugate such as an antibody-antigen or its equivalent. Then, the lectin-conjugate is isolated from the reaction product mixture by one of a number of alternative techniques involving one or more of the following types of reaction; (1) reversible reaction of the lectin with an insolubilized sugar to isolate lectin from the remainder of the mixture, (2) reaction of one immunological component (e.g., antibody) bonded to the lectin with an insolubilized corresponding component (e.g., antigen) to separate the antibody components from the remainder of the reaction mixture, and (3) filtration of the reaction components to separate on the basis of product molecular weight, size and/or shape of the components.

Abstract: A method for the determination of one or more components of an immunological conjugate, e.g., antigens, of a fluid sample in a competitive or sandwich technique in which the conjugate is labelled and separated from its reactive mixture by reversible attachment to a solid surface. In a preferred embodiment, the solid surface comprises insolubilized sugar which reversibly bonds to a lectin covalently bonded to one member of the conjugate. After separation of such solid surface from the remainder of the reaction mixture, the insolubilized sugar-lectin bond is broken by contact with a sugar solution which displaces the labelled lectin compound. The immunological components including label and lectin may be preincubated in a homogeneous solution prior to reversible attachment to the sugar solid surface. For a competitive system, a sample containing antigen is incubated with a known quantity of labelled antigen and lectin-bound antibody.