An interaction is inferred when a bait protein is affinity captured from cell extracts by either polyclonal antibody or epitope tag and the associated interaction partner identified by Western blot with a specific polyclonal antibody or second epitope tag. This category is also used if an interacting protein is visualized directly by dye stain or radioactivity. Note that this differs from any co-purification experiment involving affinity capture in that the co-purification experiment involves at least one extra purification step to get rid of potential contaminating proteins.

Interaction inferred from the presence of two or more protein subunits in a partially purified protein preparation. If co-fractionation is demonstrated between 3 or more proteins, then add them as a complex.

Interaction inferred from the presence of two or more protein subunits in a partially purified protein preparation. If co-fractionation is demonstrated between 3 or more proteins, then add them as a complex.

An interaction is detected between purified proteins in vitro.

A genetic interaction is inferred when mutations in separate genes, each of which alone causes a minimal phenotype, result in a significant growth defect under a given condition when combined in the same cell.

A genetic interaction is inferred when mutations or deletions in separate genes, each of which alone causes a minimal phenotype, result in lethality when combined in the same cell under a given condition.

A genetic interaction is inferred when mutations or deletions of one gene rescues the lethality or growth defect of a strain mutated or deleted for another gene.