An easy method for comparing antibody affinities to related antigens.

: Four different Aleutian disease virus (ADV) isolates were coated to 1/4" polystyrene balls. The binding capacity of these balls against different mouse hybridoma antibodies prepared against each of the ADV isolates was investigated in two ways. The different ADV-coated balls were either mixed in a tube (competition between balls for antibody), or they were allowed to react separately with antibody (no competition). The difference in competitive and non-competitive binding values allows a comparison of antibody affinity against the four ADV isolates. Examples are given, where two hybridoma antibodies react better with the Danish isolate than with the three American isolates.