Abstract: Intact mRNA was isolated from adult worms of S. japonicum by guanidine hydro-chloride/CsCl -procedure and Oligo(dT) cellulose chromatography. Translation of the mRNA in a rabbit reticulocyte lysate gave positive incorporation of 35S-methionine into synthe-sized proteins. The translation products from schistosome mRNA are precipitable with serum from infected rabbits, showing that serum could recognize the protein determinante by counter electrophoresis radioautography. The experiments described here open the way to clone the antigen genes of 5. japonicum.