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).

Top2 interacted with mle and msl-1, but not with msl-2 or msl-3 in this assay.

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