The dot-immunobinding assay of Hawkes et al. [R. Hawkes, E. Niday, and J. Gordon (1982) Anal. Biochem. 119, 142-147] has been modified such that many antibody solutions are screened simultaneously on dots of antigen applied to a single sheet of nitrocellulose using very small amounts of both antigen and antibody solutions. This method is also used in the assay of antibody binding on dots of components of the antigen after enzymatic digestion and chromatographic fractionation and to dots of compounds which may be chemically related to the antigen. An aluminum template for screening Western blots with a number of different antibody solutions on a single sheet of nitrocellulose is also described. Possible applications of the dot-immunobinding assay in screening for virus are discussed.