Factors were detected on polytene chromosomes using antibodies (to proteins) or biotinylated antisense probes (to ncRNA). The PLA signal develops only if probes to the two factors are in close proximity to each other (within tens of nanometers).

Source was larval salivary gland of wild-type fly line; proteins produced from endogenous gene.

Source was yeast cell line; bait produced as transgenic fusion protein; prey produced as transgenic fusion protein (prey was previously cloned reagent).

Two-hybrid system: yeast GAL4-BD/GAL4-AD; positive control.