High-performance capillary electrophoresis of SDS-proteins using pullulan solution as separation matrix

Area of Science:

• Analytical Chemistry
• Biochemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) is a powerful separation technique.
• Protein analysis requires robust and reproducible methods.
• Conventional CE coatings can lack stability, especially under alkaline conditions.

Purpose of the Study:

• To develop a stable capillary electrophoresis (CE) method for protein separation and molecular mass determination.
• To utilize pullulan solution as a separation matrix in CE.
• To improve capillary stability and reproducibility compared to existing methods.

Main Methods:

• Sodium dodecyl sulphate (SDS) capillary electrophoresis was employed.
• Fused-silica capillaries were coated with linear polyacrylamide via Si-C linkages.
• Pullulan solution was used as the separation matrix.
• Coating stability was tested under alkaline buffer conditions (pH 9.2).

Main Results:

• The developed capillary coating demonstrated enhanced stability under alkaline conditions compared to siloxane-linked coatings.
• Electroosmotic flow was significantly reduced, allowing the use of low-viscosity polymer solutions like pullulan.
• Excellent linearity was observed between protein mobility and logarithm of molecular mass.
• High reproducibility was achieved, with relative standard deviation of migration times below 0.5%.

Conclusions:

• The pullulan-stabilized CE system offers improved capillary lifespan and separation reproducibility.
• This method provides a reliable approach for protein molecular mass determination.
• The enhanced stability and reduced electroosmotic flow make this technique suitable for various protein analysis applications.