Stabilization of phosphatidylcholine coatings in capillary electrophoresis by increase in membrane rigidity

Cholesterol‐rich membrane coatings for interaction studies in capillary electrophoresis: Application to red blood cell lipid extracts

“…In runs at 457C, the EOF of the pure DPPC coating increased when several injections were made to the same capillary, suggesting that, owing to the increase of fluidity, the coating was leaking out of the capillary. The increase in EOF was expected since we had previously found that the rigidity of the coating is important in maintaining its stability in the capillary [3]. Clearly some kind of PC base for the coating solution is needed (Fig.…”

“…The emphasis was on the rigidity and stability of the phospholipid coating. In a previous work, we have described a simple method for coating a fused-silica capillary with phospholipids [1] and showed how temperature and addition of divalent cations [3] or the surfactant CTAB [29] affect the rigidity of the phospholipid phase and the stability of the coating for CE.…”

“…This in turn has great influence on the coating stability and separation in CE, as presented earlier. With DPPC in the more rigid gel phase, the EOF is suppressed and the coating is stabilized, properties which are essential for protein separations [3]. In preparing liposomes by extrusion it is important to keep the temperature of the lipid solution above the T m .…”

Capillary electrophoresis of proteins 2003–2005

“…The phospholipid coating was more efficient in reducing EOF, if it was stabilized by the addition of divalent cations (Ca 21 , Mg 21 , Zn 21 ) or by working in the gel-state region of the phospholipid [52]. Similar zwitterionic surfactants 1-palmitoyl-2-oleyol-sn-glycero-3-phosphocholine [54] and 1,2-dioleyol-sn-glycero-3-phosphocholine [55] were also used as a dynamic coating, the latter after a free-radical-initiated polymerization.…”

“…Various surfactants have been used to reduce EOF and protein adsorption on the wall, including the cationic detergent didodecyldimethylammonium bromide [47], neutral surfactant Brij 35 modifying hydrophobic channels in a poly(dimethyl siloxane) (PDMS) microchip [48], zwitterionic sulfobetains [49,50], zwitterionic 1,2-dilauryloylsn-phosphatidylcholine [51,52], and 1,4-didecyl-1,4-diazoniabicyclo[2,2,2]octane dibromide [53]. The phospholipid coating was more efficient in reducing EOF, if it was stabilized by the addition of divalent cations (Ca 21 , Mg 21 , Zn 21 ) or by working in the gel-state region of the phospholipid [52].…”