Purification of equine chorionic gonadotropin (eCG) using magnetic ion exchange adsorbents in combination with high-gradient magnetic separation.

This research article presents an optimized and efficient method for purifying equine chorionic gonadotropin (eCG) from horse serum, using magnetic ion exchange adsorbents in conjunction with a high-gradient magnetic fishing (HGMF) system. This method resulted in eCG purification yields of 53% from single HGMF cycles and up to 80% from multicycle experiments.

Research Objective

• The research aimed to develop an improved and more economical process for the purification of the glycoprotein equine chorionic gonadotropin (eCG) from horse serum. eCG is typically purified through a multi-step process that requires several precipitation steps and chromatography, a procedure that can be costly and time-consuming.

Method and Design

• The researchers proposed a more streamlined purification process that uses magnetic ion exchange adsorbents and a high-gradient magnetic fishing (HGMF) system. This method requires significantly lesser solvent and steps relative to conventional procedures.
• The HGMF system utilizes magnetic adsorbents to capture and remove the target protein from the serum. These adsorbents can be separated and reused, potentially enhancing the efficiency and sustainability of the process.
• Before implementing the HGMF process, the team optimized binding and elution conditions for the target protein at the milliliter scale and characterized the magnetic filter for particle separation.

Implementation and Process

• The proposed purification process for eCG comprised the following steps: pretreatment of horse serum, binding of eCG to magnetic ion exchange adsorbents in a batch reactor, recovery of loaded functionalized adsorbents using HGMF, washing of loaded adsorbents to remove unbound proteins, and finally, elution of the target protein.
• The researchers then automated the entire HGMF process and conducted either multiple single-cycle or multicycle operations using batches of pretreated serum of up to 20 liters.

Results and Findings

• The HGMF process returned eCG purification yields of approximately 53% in single-cycle mode and up to 80% in multicycle mode.
• The method also displayed impressive purification and concentration factors of around 2,500 and 6.7, respectively, demonstrating the effectiveness and efficiency of the new method.