Open-channel isolectric focusing in thermally engendered pH gradients

✍ Scribed by Charles H. Lochmuüller; Steven J. Breiner; Christopper S. Ronsick

• Book ID: 104145677
• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 666 KB
• Volume: 480
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)84298-9

✦ Synopsis

The use of thermally formed pH gradients permits macromolecular separations in open-channel isoelectric focusing (IEF), simplifying product recovery, shortening run times and eliminating costly carrier ampholytes.

Because of these unique advantages and other limitations this IEF method may effect purifications on a preparative scale more effectively than on an analytical scale where other IEF methods may cover a larger pH range. Heat exchangers at both ends of a 3.18 mm x 5.0 mm x 28.0 mm channel generated the temperature gradient (4°C cm-'). Owing to the large temperature dependence of the pH (dpH/dT= -0.028 K-l), the Tri-HCl buffer formed the pH gradient in the free solution. In a 25 V cm-' electric field, a dilute mixture of hemoglobin variants A and S (cu. 0.8 mg ml-', isoelectric points 6.98 and 7.2, respectively) were separated and concentrated by a factor of 20.