抗体存在多种系统时,会出现多条沉淀线(弧)。依据沉淀线(弧)可以定性抗原。此法操 作简便、灵敏度高,是最为常用的免疫学测定抗原和测定抗血清效价的方法(见图8-4) 图8-4免疫双向扩散法 Precipitin reactions in gels: immuno-double-diffusion dentity anti-1 b non-identity ant-1,24 c. partial identity Fig8-4 In immuno-double-diffusion, agar gels are poured onto slides and allowed te set, wells are then punched in the gel and the test solutions of antigen(Ag)and antibody (ab) are added. The solutions diffuse out and where Ag and Ab meet they bind to each other, cross-link and precipitate leaving a line of precipitation. This technique may be used to determine the relationship between antigens and a particular test antibody Three basic patterns appear. In reaction(a) the precipitin arcs formed between the antibody and the two test antigen fuse, indicating that the antibody is precipitating identical epitopes in each preparation(epitope 1). This does not mean that the antigens are necessarily identical, they are only identical in as far as the antibody cannot distinguish a difference In reaction( b) the162 抗体存在多种系统时，会出现多条沉淀线（弧）。依据沉淀线（弧）可以定性抗原。此法操 作简便、灵敏度高，是最为常用的免疫学测定抗原和测定抗血清效价的方法（见图 8-4）。 图 8-4 免疫双向扩散法 Fig8-4 In immuno-double-diffusion, agar gels are poured onto slides and allowed to set, wells are then punched in the gel and the test solutions of antigen(Ag) and antibody(Ab) are added. The solutions diffuse out and where Ag and Ab meet they bind to each other, cross-link and precipitate leaving a line of precipitation. This technique may be used to determine the relationship between antigens and a particular test antibody. Three basic patterns appear. In reaction(a) the precipitin arcs formed between the antibody and the two test antigen fuse, indicating that the antibody is precipitating identical epitopes in each preparation(epitope 1). This does not mean that the antigens are necessarily identical, they are only identical in as far as the antibody cannot distinguish a difference. In reaction(b) the