Leaf-Dip Serology* *Published with the approval of the Director as paper No. 2952 Journal Series, Nebraska Agricultural Experiment Station. Supported in part by a grant from the National Science Foundation

Publisher Summary This chapter discusses leaf dip serology. Without elaborate purification, a virus can be classified on the basis of gross morphology by dipping the infected leaf in a drop of water. The leaf-dip procedure is modified by incorporating virus-specific antiserum into the drop and making the initial observation of the virus, a positive method of identification. Antibody-covered antigen when negatively stained has a thick, dark appearance, making labeling of the antibody with electron- dense material unnecessary. By this procedure, plant viruses can be easily distinguished even when mixed with morphologically similar particles. The advantages of the test are that: (1) the antiserum sample can be stored conveniently for immediate use; (2) it requires very small amounts of antiserum; (3) the reaction of the virus rod and antibodies can be observed directly; and (4) the occurrence of other morphologically similar viruses in the test does not obscure the test or give false positive results.