A two-phase scheme for sampling all possible interactions between two arrays. The strategy is illustrated for an array of 96 BD strains and an array of 96 AD strains. In the first step (Phase 1), the 96 AD clones are pooled, and the pool is mated with the BD array. This will reveal which of the BD-fused proteins interacts with one or more of the 96 AD-fused proteins. In the second step (Phase 2), positive BD clones are individually mated with the AD array. This will reveal which AD(s) in the array interact(s) with the BD. If there is only one interaction between the two arrays, this pooling scheme will require only two mating procedures to sample 9216 possible combinations.
