Western blotting was done to evaluate the antigenicity of the expressed b-galactosidase. Liposomes containing b-galactosidase were disrupted by adding 100 ll of Cell lytic B buffer to 55 ll of liposome suspension. After adding electrophoresis loading-buffer (60 mM Tris-HCl, pH 6.8, with 25% glycerol and 2% SDS containing 0.1% bromophenol blue solution, and b-mercaptoethanol), the samples were heated for 5 min at 95°C and electrophoresed at 125 V under reducing conditions, in a 10% SDS-polyacrylamide gel (Bollag and Edelstein 1991) . After gel electrophoresis, antigen bands were transferred to a nitrocellulose membrane by using a dry Western blotting system (iBlot, Invitrogen, Frederick, MD) in 6 min. After blotting the free sites were blocked with 1% non-fat milk-powder in PBS containing 0.05% Tween 20 (PBS-T). Next, the membrane was incubated with a solution of goat anti-b-galactosidase polyclonal antibody in PBS-T containing 0.1% non-fat milk powder. The membrane was then washed to remove the unbound antibody and incubated with Cy-5-labeled, rabbit IgG anti-goat immunoglobulin. The blotted antigen-antibody complexes were visualized by a fluorescence using a Typhoon imager (Amersham Corporation, Arlington Heigths, IL, USA).