In vitro translation of mRNA from Toxocara canis larvae.

300 micrograms of total RNA was extracted from 1 ml of packed Toxocara canis larvae by centrifugation through a 5.7 M cesium chloride cushion. 60 micrograms of polyadenylated messenger RNA was separated from 300 micrograms of total RNA in an oligothymidylic acid-cellulose gel column. The in vitro translation of the mRNA, isolated from T. canis larvae, was carried out using the rabbit reticulocyte cell-free translation system. Incorporation of [35S]methionine into trichloroacetic acid precipitable material in the lysate containing mRNA was 4-5 times greater than that of control. Translation products were analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by autoradiography. Many polypeptides ranging in molecular weight from 10000 to 100000 were synthesised in the lysate. A T. canis positive human serum was mixed with translation products to form antigen-antibody complexes, which were then absorbed by Staphylococcus aureus Cowan 1 strain and analysed by the autoradiography of SDS-PAGE. Three antigenic polypeptides with molecular weights of 49000, 27000 and 22000 which reacted specifically with IgG antibody in T. canis positive human serum, were demonstrated. The 27000 MW polypeptide reacted particularly strongly with the IgG antibody.