| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1201931 | Journal of Chromatography A | 2012 | 7 Pages |
A sequential surfactant bilayer/diblock copolymer coating was previously developed for the separation of proteins. The coating is formed by flushing the capillary with the cationic surfactant dioctadecyldimethylammonium bromide (DODAB) followed by the neutral polymer poly-oxyethylene (POE) stearate [22]. Herein we show the method development and optimization for capillary isoelectric focusing (cIEF) separations based on the developed sequential coating. Electroosmotic flow can be tuned by varying the POE chain length which allows optimization of resolution and analysis time. DODAB/POE 40 stearate can be used to perform single-step cIEF, while both DODAB/POE 40 and DODAB/POE 100 stearate allow performing two-step cIEF methodologies. A set of peptide markers is used to assess the coating performance. The sequential coating has been applied successfully to cIEF separations using different capillary lengths and inner diameters. A linear pH gradient is established only in two-step CIEF methodology using 3–10 pH 2.5% (v/v) carrier ampholyte. Hemoglobin A0 and S variants are successfully resolved on DODAB/POE 40 stearate sequentially coated capillaries.
► A versatile hydrophilic semi-permanent coating has been developed for capillary isoelectric focusing. ► The coating is easy to prepare, low cost and provides controllable suppressed EOF. ► The coating can be applied to both single-step and two-step capillary isoelectric focusing separations. ► The coating can be applied to different length and inner diameter capillaries. ► Linear pH gradients and separation of hemoglobin variants have been achieved using the developed coating.
