Abstract: Red Blood Cells (RBC's) are removed from whole blood samples by contacting the whole blood sample with a solution containing an acid selected from the group consisting of acetic acid, citric acid, ascorbic acid, lactic acid, maleic acid, malic acid, and malonic acid. The agglutinated RBC's are then removed from the resultant suspension by procedures of filtration, centrifugation or decantation, leaving an essentially RBC-free serum or plasma sample.

Abstract: A method and apparatus for conducting specific binding pair assays, such as immunoassays, is described. A porous membrane capable of non-bibulous lateral flow is used as assay substrate; a member of the binding pair is affixed in an indicator zone defined in the substrate. The sample is applied at a position distant from the indicator zone and permitted to flow laterally through the zone; any analyte in the sample is complexed by the affixed specific binding member, and detected. A novel method of detection employs entrapment of observable particle in the complex. Blood is a particularly preferred sample as the red blood cells can be used as the observable particles for detection of the complex.

Abstract: Human chorionic gonadotropin (HCG) is detected by enzyme immunoassay by bonding biotinylated antibody to an avidin coupled paper disc, reacting the antibody on the disc with the solution suspected of containing HCG, and determining the amount of HCG on the disc by enzymatic assay detection techniques.

Abstract: A system for conducting an immunoassay in a single chamber, by concentrating antibodies for antigenic components on microbeads treated for binding immunological components, physically separating the fluid from which the immunological active component is separated, and determining the amount of immunological component collected on the beads, comprising a multiple-chamber dispensing cylinder.

Abstract: A method and apparatus for conducting an immunoassay. The apparatus features a cylindrical tube having one open end into which a plunger filter assembly is slidably fitted. The filter assembly is composed of a plunger filter cylinder open at both ends, a seal fixed to the proximal end of the plunger filter cylinder and a dome-shaped filter inside of and closing the proximal end of the plunger filter cylinder, and beads sensitized with an immunologically reactive material, such as an antibody.