Coalescence of cells or other membrane-bound entities is facilitated by anchoring an outwardly projecting first oligonucleotide in one member and an outwardly projecting second oligonucleotide, complementary to the first, in a second member and incubating under hybridizing conditions. Liposomes may be coalesced with cells to deliver hydrophilic agents thereto, such as DNA probes or drugs. Kits containing complementary oligonucleotides containing hydrophobic anchoring moieties may be used.