THE STUDY OF AFRICAN .HORSESICKNESS VIRUS BY THE AGAR DOUBLE.DIFFUSION PRECIPITATION TEST. l-ST ANDARDIZATION OF THE TECHNIQUE

Since the introduction of agar double diffusion test to the study of antigen-antibody reaction by Ouchterlony on 1948, (16) the technique has extensively been used in identification and immunological research studies on different viruses including those of Arbovirus group. (1,2,3,6,8,9,14,15) The first application of gel diffusion to the study of African horsesickness virus, a member of the Arbovirus group, was reported by Huq and Ansari (7), who employed it as a laboratory tool for the diagnosis of the disease. Serum obtained from rabbits hyperimmunizd by 5 weekly intravenous injections of 1 m 1. of a 10% infected horse splenic tissue ,suspension in saline was mostly used in the test. ForiT.alized saline suspension of splee1. tissues of infe::ted animais, and in a few experiments virulent blood in O.CG. or bufferd glycerine, were used as antigens. It was statd that two pre::ipitin lines were foriT.ed when such antigens and antiserum, were diffused towards each other through an agar medium. With the reœ1.t advanceme1.t in the study of horsesickrtess virus, especially after successful adaptation of the virus in tissue culture (13,17), it was thought useful to further investigate the gel diffusion test on the study of this virus using antigens prepared from different host systems and antisera obtained from different animaIs. An extensive study is now in progress tocharacterize the horsesickness viral antigen properties, pre::ipitating antibody response of animaIs to the virus, and so on. The findings will be considered in the subse'lUe1.t !')aTJeTS. The pre~ent communication describes the spe::ificity of pre::ioitin reJ.ctions between horœ· sickness antigen-antibody systems and deals mostly with the standardization of the technique.