Abstract: A method for increasing the binding activity of specific binding members bound to a solid phase material, e.g., a particle, that has been sterically stabilized. This increase in binding activity is brought about by degrading a steric stabilizer on the surface of the solid phase material. The method involves both immobilizing a specific binding member on the surface of a solid phase material and degrading a steric stabilizer on the surface of that solid phase material. In the preferred embodiment, the method involves the immobilization of a specific binding member on the surface of the sterically stabilized solid phase material, with subsequent degradation of the steric stabilizer.

Abstract: A method for performing a diagnostic immunoassay by a solid phase separation. To a reaction mixture of a test sample and labeled antibody, which forms a complex of any analyte present in the test sample, is added a solid phase material having a compound capable of binding any excess labeled antibody. The solid phase material is chosen to rapidly settle whereby a solid and liquid phase is formed. The liquid phase can then be extracted to measure the amount of analyte-labeled antibody present therein.

Abstract: A device and method for permitting the separation of plasma or serum from whole blood. The device comprises a matrix of hydrophilic sintered porous material to which at least one red blood cell agglutinating agent has been applied. According to a first method of using the device, a sample of whole blood is applied to a first end of the matrix and the red blood cells within the sample come in contact with the agglutinating agents present in the matrix. The blood cells agglutinate, and are entrapped in the interstices of the matrix, while substantially blood-cell-free serum or plasma accumulates near the outlet of the device. A filter means in liquid receiving relationship with the matrix functions to wick the serum of plasma from the matrix.According to an alternative aspect of the invention, a filter means in liquid receiving relationship with the outlet of the matrix functions to retain any blood cells which pass through the matrix as the filter means wicks the plasma or serum from the matrix.

Abstract: A method for performing a diagnostic immunoassay by solid phase separation for digoxin. To a reaction mixture of a test sample and labeled anti-digoxin antibody, which forms a complex of any digoxin present in the test sample, is added a solid phase material having an immobilized ouabain triacetate derivative compound capable of binding any excess labeled antibody. The solid phase material is chosen to rapidly settle whereby a solid and liquid phase is formed. The liquid phase can then be extracted to measure the amount of digoxin-labeled antibody present therein. Ouabain triacetate derivative compounds possess sufficient affinity for anti-digoxin antibodies, and are therefore useful in a solid phase separation based digoxin immunoassay for settling out such antibodies without contributing to undesired background interference.

Abstract: A method for performing a diagnostic immunoassay by solid phase separation for digoxin. To a reaction mixture of a test sample and labeled anti-digoxin antibody, which forms a complex of any digoxin present in the test sample, is added a solid phase material having an immobilized ouabain triacetate derivative compound capable of binding any excess labeled antibody. The solid phase material is chosen to rapidly settle whereby a solid and liquid phase is formed. The liquid phase can then be extracted to measure the amount of digoxin-labeled antibody present therein. Ouabain triacetate derivative compounds possess sufficient affinity for anti-digoxin antibodies, and are therefore useful in a solid phase separation based digoxin immunoassay for settling out such antibodies without contributing to undesired background interference.