Homobifunctional reagents single-step cross-linking

B/s-imidoesters like DMS may be used to couple proteins to PE-containing liposomes by cross-linking with the amines on both molecules (Fig. 353). However, single-step cross-linking procedures using homobifunctional reagents are particularly subject to uncontrollable polymerization of protein in solution. Polymerization is possible because the procedure is done with the liposomes, protein, and cross-linker all in solution at the same time. 

The problems of indeterminate conjugation products are amplified in single-step reaction procedures using homobifunctional reagents (Chapter 4). Single-step procedures involve the addition of all reagents at the same time to the reaction mixture. This technique provides the least control over the cross-linking process and invariably leads... 

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