New aqueous two phase system comprising polyethylene glycol and xanthan

Area of Science:

• Biochemistry
• Polymer Science
• Separation Science

Background:

• Aqueous two-phase systems (ATPS) are widely used for bioseparation.
• Conventional ATPS often exhibit significant viscosity differences between phases.
• Polyethylene glycol (PEG) and xanthan are common polymers for ATPS formation.

Purpose of the Study:

• To report a new aqueous two-phase system composed of polyethylene glycol (PEG) and xanthan gum.
• To characterize the phase diagram and physicochemical properties of this novel ATPS.
• To evaluate the partitioning behavior of a model protein (Bovine Serum Albumin, BSA) within the system.

Main Methods:

• Preparation and characterization of the polyethylene glycol-xanthan aqueous two-phase system.
• Determination of the phase diagram and composition of each phase.
• Measurement of phase viscosity.
• Protein partitioning studies using Bovine Serum Albumin (BSA) as a model.

Main Results:

• The phase composition of the bottom phase remained relatively constant (1.6-1.8% PEG, 0.24-0.28% xanthan).
• The top phase composition showed significant variation (4-5% PEG, 0.05-1.37% xanthan).
• Unlike conventional systems, the top phase exhibited high viscosity, comparable to the bottom phase.
• Bovine Serum Albumin (BSA) was found to partition exclusively into the bottom phase.

Conclusions:

• A novel aqueous two-phase system of PEG and xanthan gum has been successfully developed.
• This system possesses unique characteristics, including high and comparable viscosities in both phases.
• The system demonstrates effective selective partitioning of BSA into the bottom phase, suggesting potential for bioseparation applications.