Trans-elution: A method for the purification of components of complex biological extracts

Abstract Trans-elution is a simple and rapid technique allowing the purification of macromolecules trapped in polyacrylamide gels following electrophoresis. This method of purification consists of the sideways transfer of the macromolecules under the influence of an electric field from the gel slab toward an inert support. In contrast to the role of nitrocellulose used in the “Western blotting” technique, in this case the support does not bind the macromolecules. It consists of a network capable of retaining the buffer by capillarity. The electroeluted proteins remain in solution in the buffer and it is thus easy to recover them by spin-drying the support. The support material is either glue-free paper or glass fiber paper. Small concentrated samples are obtained at high yield. The procedure does not require gel slicing, thus avoiding both manipulation of the at high yield. The procedure does not require gel slicing, thus avoiding both manipulation of the gel and errors in the localization of the fractions to be purified. In a single step all the proteins fractionated on the gel may be eluted. The trans-elution technique has been applied to the purification of Plasmodium falciparum and Toxoplasma gondii antigens, the causative agents of malaria and toxoplasmosis, respectively.