Cationized hydroxyethylcellulose as a novel, adsorbed coating for basic protein separation by capillary electrophoresis

Abstract

We present cationized hydroxyethylcellulose (cat-HEC) synthesized in our laboratory as a novel physically adsorbed coating for CE. This capillary coating is simple and easy to obtain as it only requires flushing the capillary with polymer aqueous solution. A comparative study with and without polymers was performed. The adsorbed cat-HEC coating exhibited minimal interactions with basic proteins, providing efficient basic protein separations with excellent reproducibility. Under broad pHs, the amine groups are the main charged groups bringing about a global positive charge on the capillary wall. As a consequence, the cat-HEC coating produced an anodal EOF performance. A comparative study on the use of hydroxyethylcellulose (HEC) and cat-HEC as physically adsorbed coatings for CE are also presented. The separation efficiency and analysis reproducibility proved that the cat-HEC polymer was efficient in suppressing the adsorption of basic proteins onto the silica capillary wall. The long-term stability of the cat-HEC coating in consecutive protein separation runs has demonstrated the suitability of the coating for high-throughput electrophoretic protein separations.

Hydroxyethylcellulose‐graft‐poly (4‐vinylpyridine) as a novel, adsorbed coating for protein separation by CE

“…The high-efficient separations and stability of the adsorbed HEC-g-P4VP coating proved the high quality of this coating for protein analysis by CE. The plausible mechanism of adsorption was that the HEC-g-P4VP chain is bound to the silanol groups effectively through ionic bond and hydrogen bond [15]. Owing to the co-operation of hydrogen bond and ionic bond, the velocity of desorption is becoming slow.…”

“…According to our previous work, although excellent separation efficiency could be achieved by using fresh HEC-coated capillary, HEC is ineffective to reduce the protein adsorption after several runs because the HEC coating is easy to be washed away from the wall by the buffer solution for its higher hydrophilicity. Thus, the HEC coating yields poorer migration times repeatability (RSDsZ3.0%) [15]. Therefore, in order to solve the insufficient adsorption of hydrophilic polymer on the capillary wall, a variety of positively charged polymers have been used as both statically and dynamically adsorbed wall coatings for the analysis of basic proteins [16][17][18][19][20][21].…”

Synthesis of hydroxyethylcellulose‐graft‐poly(N, N‐dimethylacrylamide) copolymer by ATRP and as dynamic coating in capillary electrophoresis

“…The results shown that the adsorption phenomenon between the proteins (positively charged) and the capillary wall (negatively charged) is so strong that leads to the analysis of protein mixtures using the bare silica capillary is impossible. 13 …”

Poly(ethylene glycol)‐coated microfluidic devices for chip electrophoresis

“…This method is easily adaptable for microfluidic systems. For this purpose, several surface-active materials, mainly polymer-based such as poly(vinyl alcohol) (PVA) [5], poly(ethylene glycol) (PEG) [6], hydroxyethylcellulose [7], cationized-hydroxyethylcellulose [8], poly(vinyl pyrrolidone) [9] or different copolymers [10][11][12][13] were described in the CE and MCE literature. Other suitable surface-active compounds are surfactants [14,15], polyelectrolyte multilayers [16,17] or ionic liquids [18].…”