Single-input divergent flow IEF for preparative analysis of proteins

Area of Science:

• Analytical Chemistry
• Biochemistry
• Separation Science

Background:

• Continuous flow isoelectric focusing (IEF) offers potential for high-resolution separations.
• Previous IEF instrument designs required further optimization for stability and preparative applications.

Purpose of the Study:

• To extend and test an instrument for continuous divergent flow IEF.
• To evaluate the device's performance for long-term preparative analysis and analyte focusing.

Main Methods:

• A trapezoidal separation area with a porous, nonwoven textile bed was utilized.
• Continuous sample introduction at 0.18 mL/min with strategically placed electrodes was employed.
• Dynamic equilibrium state and long-term stability experiments were conducted using pI markers, hemoglobin, and cytochrome C.

Main Results:

• Analyte zones and pH gradients separated and focused near the input, with resolution increasing along the separation space.
• Long-term stability experiments (over 15 hours) showed sustained focusing and separation of analytes.
• Deviations in focusing positions ranged from 1.26 to 3.96% of the bed output width, indicating high stability.

Conclusions:

• The developed continuous divergent flow IEF instrument is suitable for preparative analysis.
• The device provides stable and high-resolution separation of analytes under dynamic equilibrium conditions.
• The design demonstrates robustness for extended analytical runs.