Kits for the multiplexed detection of the binding of, or interaction between, one or more ligands and target antiligands are provided. Detection involves the release of identifying tags as a consequence of target recognition. The kits include sets of electrophoretic tag probes or e-tag probes, a capture agent and optionally a cleaving agent. The e-tag probes comprise a detection region and a mobility-defining region called the mobility modifier, both linked to a target-binding moiety. In using the kits, target antiligands are contacted with a set of e-tag probes and the contacted antiligands are treated with a selected cleaving agent resulting in a mixture of e-tag reporters and uncleaved and/or partially cleaved e-tag probes. The mixture is exposed to a capture agent effective to bind to uncleaved or partially cleaved e-tag probes, followed by electrophoretic separation. In a multiplexed assay, different released e-tag reporters may be separated and detected providing for target identification.