Disclosed are general and “substantially pure” branched discrete polyethylene glycol constructs useful in attaching to a variety of biologically active groups, for example, preferential locators, as well as biologics like enzymes, for use in diagnostics, e.g. imaging, therapeutics, theranostics, and moieties specific for other applications. In its simplest intermediate state, a branched branched discrete polyethylene glycol construct is terminated at one end by a chemically reactive moiety, “A”, a group that is reactive with a biologic material that creates “A”, which is a biologically reactive group, connected through to a branched core (BC) which has attached at least two dPEG-containing chains, indicated by the solid line, , having terminal groups, which can be charged, non-reactive or reactable moieties and containing between about 2 and 64 dPEG residues.
