| 摘要 |
<p>A sensitive direct immunoassay system is provided for the detection of an antigen associated with hepatitis in body fluids. An antibody which reacts with a hepatitis antigen or antigens and which is uniformly bonded to an insoluble member comprising a polymeric material having irregular surfaces, is incubated with a test sample. During this first 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 comprising immunochemically reactive hepatitis antibody conjugated with a functional enzyme such as alkaline phosphatase. During the second incubation, the tagged antibody reacts with antigen fixed to the insoluble member in the first incubation. Thus, a "sandwich" is formed of an insoluble member- antibodyantigen- enzyme tagged antibody. After the second incubation, the member is washed again to remove unreacted enzyme-antibody conjugate reagent. The member is then exposed to a substrate which is induced by the now immobilized enzyme to produce a detectable end product. The enzyme-antibody conjugate 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 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. All reagents for the test may be conveniently furnished in the form of a kit which has an extended shelf life and greatly simplifies the procedure.</p> |
