Antibodies to serum hepatitis are coupled to carbohydrate macro particles which are then contacted with blood fluids, suitably plasma, which are believed to contain serum hepatitis antigen. The serum hepatitis antigen is thus complexed with the bound antibody and the particles bearing both the antibody and the antigen are removed from the blood fluid. The antigen is then cleaved from the antibody by alkaline treatment, and may, if desired, be itself isolated, suitably by dialysis. The antibody/agarose complex is then available for recycling in a further batch of contaminated blood fluids. There is also disclosed a novel method of highly sensitive measurement of the extent of contamination of blood fluids with serum hepatitis antigen.
The presence of hepatitis B antigen in serum or plasma can be detected by this technique. Commercially available imitation or cultured pearls coated with antibody to hepatitis B antigen are first reacted with the sample and subsequently reacted with radioactively labeled antibody to hepatitis B antigen. Hepatitis B antigen present in the sample forms a complex consisting of non-radioactive antibody-antigen-and radioactive antibody. The radioactivity emanating from these complexes on pearls is measured. This is indicative of the extent of binding of radioactive antibody and thereby indicating the presence or absence of hepatitis B antigen in an unknown sample.
Free analytes in samples containing free analytes and receptorbound analytes are determined by absorbing at least a portion of free analyte from the sample with insolubilized receptor or receptor which is then made insoluble, washing the insoluble receptor, adding labelled sample analyte or labelled sample analyte receptor, incubating, washing the insoluble phase free of the soluble phase and determining the label in either phase. The method solves a long standing need in the assay of free thyroid hormones.
4642285 - Sandwich EIA for antigen - Owned by Diamedix Corporation (Miami, FL) [*] Notice:The portion of the term of this patent subsequent to October 2, 2001 has been disclaimed.
A sensitive direct immunoassay system is provided for the detection of an antigen in body fluids. A single antibody which reacts with an 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 substrate which is converted by the enzyme to produce an end product. The tagged antibody reagent will be fixed in the second incubation only if antigen was present in the sample. The amount of enzyme tagged antitbody fixed is proportional to the amount of antigen or antigens present in the test sample up to the maximum capacity of the test. The concentration of the end product, and hence the amount of antigen or antigens, is determined by a spectrophotometer which measures the optical absorption of light by the end product. This readout is then compared against a standard value for both antigen negative and antigen positive samples.
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. The tagged antibody reagent will be fixed in the second incubation only if antigen was present in the sample. The amount of enzyme tagged antibody fixed is proportional to the amount of antigen of antigens present in the test sample up to the maximum capacity of the test. The concentration of the end product, and hence the amount of antigen or antigens, is determined by a spectrophotometer which measures the optical absorption of light by the end product. This readout is then compared against a standard value for both antigen negative and antigen positive samples.
