Abstract: A therapeutic apparatus for the removal of a harmful agent from blood is provided in the form of an array of hollow fiber bundles connected in parallel, wherein the interior surfaces of the individual hollow fibers are coated with a covalently bound proteinaceous or other immunoadsorbent selected for specific removal of the harmful agent. In the disclosed method the apparatus is optionally connected as an extracorporeal shunt between the artery and vein of a patient to be treated and the blood is alternately routed through one fiber bundle while the remaining fiber bundles undergo regeneration. Specific embodiments include the removal of rheumatoid factor by covalently bound immunoglobulin G and the removal of digoxin by covalently bound anti-digoxin.

Abstract: A sensitive direct immunoassay system is provided for the detection of an antigen associated with hepatitis in body fluids. A single antibody which reacts with a hepatitis antigen or antigens and which is bonded to an insoluble member, is incubated with a test sample. During this first period of incubation a portion of an antigen present in the test sample will combine with the antibody immobilized on the insoluble member. The antibody bonded member, to which antigen is attached, is then washed and incubated with an enzyme tagged antibody reagent. During the second incubation, the tagged antibody reacts with antigen fixed to the antibody member in the first incubation. Thus, an immobilized "sandwich" is formed of an insoluble member- antibody-antigen-enzyme tagged antibody. After the second incubation, the member is washed again to remove unreacted enzyme antibody reagent. The member is then exposed to a substrated which is converted by the enzyme to produce an end product.

Abstract: A disc-shaped insoluble matrix is formed of a polymeric material having a layer of reactive groups which react with proteins binding them covalently and uniformly to its surface. An antibody adapted for use in immunoassay of antigens associated with hepatitis is covalently bonded to the reactive groups. The matrix is provided with irregular, e.g., waffle-like, surfaces designed to increase the amount of antibody that will be in contact with a test solution such as serum.