Human Anti-Ro/SS-A polyclonal antibody for ELISA. The (Ro) SS-A antigen is comprised or an acidic 60 kD protein that may also be associated with a RNA ranging in size from 80 to 112 bases). The antigenic activity of the (Ro) SS-A antigen appears to be independent of the RNA since the precipitin activity remains after treatment with RNase or separation from the RNA. Anti-(Ro) SS-A autoantibodies were described originally as precipitating autoantibodies in sera of Sjogren's Syndrome and Systemic Lupus Erythematosus patients.