Mirror image in vivo electroblotting technique, a new technique for visualizing virus particles electrophoretically transferred from infected leaves to nitrocellulose membranes

Abstract

A new technique was developed for visualizing virus particles electrophoretically transferred from infected leaves to nitrocellulose membranes. This technique was used to study the distribution of peanut mottle virus (PMV) particles in vivo. The immobilized transferable virus proteins from leaf tissue to nitrocellulose membranes were detected by an enzyme-linked immunobinding technique. The free binding groups on the nitrocellulose membrane were blocked with casein. The nitrocellulose membrane was then treated with PMV-specific antiserum. The virus-bound antibodies were located by protein A-peroxidase or protein A- alkaline phosphatase conjugate followed by the peroxidase substrate mixture, 4-chloro-l-naphthol and H 2O 2, in the first case or the alkaline phosphatase substrate mixture, 5-bromo-4-chloro-3-indolyl phosphate and Nitroblue tetrazolium in the second case. The locations of virus particles were detected by the corresponding reaction product. A mirror image was obtained on nitrocellulose membrane showing a pattern identical to that of necrotic lesions on leaf pieces but with a significantly larger size of local lesion copy, indicating the presence of virus particles in the apparently healthy tissue outside the necrotic lesion. The new technique is expected, because of its relative simplicity and sensitivity, to be useful for many other fields of biological research where the in vivo distribution of pathogens, antigenic molecules including drugs, or cells of specific antigenic molecules such as cancer or genetically engineered cells needs to be investigated.