Reagent and method for detecting the presence of hepatitis associated antigen (HAA) in blood serum. The reagent comprises anti-HAA antibodies coupled via an intermediate silane to a plurality of siliceous particles having a surface area of at least about 1 m.sup.2 /g and, if the particles are porous, an average pore diameter of at least about 1000 A. The test method comprises the steps of incubating a serum sample with the reagent to complex any HAA in the samplewith the antibodies of the reagent, incubating the reaction product with a solution of radio labelled anti-HAA antibodies to complex the labelled antibodies with any HAA that may be complexed to the reagent, separating the incubation products from the solution of labelled antibodies, and counting the radioactivity of either the separated products or the remaining solution to determine whether HAA was in the sample.
The present invention encompasses an improved method for detecting antigen or antibody bound to a solid support which involves the reaction of hapten-labeled antibody to the antigen or antibody to be detected followed by reaction of the hapten moiety with labeled antibody to the hapten and the determination of the amount of label bound to the solid support.
Liquid containing hepatitis A antibody is adsorbed on a surface. The surface is then coated with a proteinaceous material and incubated in the presence of the sample to form a complex of hepatitis A antigen and hepatitis A antibody. The complex is incubated again in the presence of excess radioactively labelled hepatitis A antibody, and the resulting radionuclide is measured.
A method and test kit are disclosed for detecting the presence of hepatitis B virus in a test specimen containing at least a portion of the DNA of the virus. A test reagent comprises cloned hepatitis B virus-DNA that has been repurified by treatment with a restriction enzyme and labelled to high specific activity with a radioactive label. The sample to be tested is fixed to a solid matrix, incubated in the presence of the test reagent under hybridization conditions and detected by hybridization to the labelled DNA probe. The uncombined HBV-DNA (labelled) is removed from the substrate, and the hybridized HBV-DNA determined by scintillation counting or by autoradiography of the substrate.
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.
