Facile laboratory method for localising biomolecules to the surface of cells and viruses

Method of localizing a sulfhydryl (-SH) group containing biomolecule to the surface of a cell membrane by mixing in a volatile reaction buffer a molar excess of the sulfhydryl (-SH) group containing biomolecule with a lipid conjugated maleimide of the structure F-S-L as defined in the specification to provide a reaction mix, incubating the reaction mix for a time and at a temperature sufficient to allow all the lipid conjugated maleimide to have reacted with the sulfhydryl (-SH) group, and freeze-drying the reaction mix to remove the volatile reaction buffer and provide a reaction product. An aqueous solution of the reaction product is contacted with the cell membrane.