Separation & Purification of Protein by Ion Chromatography

Alfa Chemistry provides you with protein purification services. Our technology is derived from ion exchange chromatography. We can provide a series of chromatographic columns, reagents and instruments for your protein purification. We also provide purification process optimization services to improve your purification efficiency.

Introduction

Ion exchange chromatography is widely used in protein research, analysis and process-scale purification. The high capacity, low cost, high resolution and buffer conditions of ion exchange chromatography make it an ideal choice for protein purification. The charged groups on the protein are provided by different amino acids in the protein, and the charged groups of the amino acids vary according to the acidity of the solution. Therefore, the total charge on the protein changes according to the pH value. The pH value at which the total charge on the protein is zero is also called the isoelectric point (pI). When purifying proteins by ion exchange chromatography, this information will help determine the best starting conditions for purification.

Fig.1 Protein purification process

Ion exchangers are divided into strong and weak ions. Strong ion exchange ligands maintain their charge characteristics in a wide pH range and keep the exchange capacity unchanged, while the exchange capacity of weak ion exchange ligands can change with the change of pH. Therefore, if the pH is higher than 9 for anion exchange or lower than 6 for cation exchange, a strong ion exchanger is required. On the contrary, if your purification is performed at a milder pH value, you need to choose from the purification results of stronger and weaker ion exchangers.

The buffer is a bridge for the dissociation of the protein from the ion exchange matrix. The charged counterions in the buffer compete with the charged groups on the protein to bind the oppositely charged groups on the stationary phase. When the protein groups are dissociated from the ionic groups on the stationary phase through electrostatic adsorption, the possibility that the ions in the mobile phase will bind to the charged groups and ionic groups on the protein is increased. Therefore, as the salt concentration increases, the protein is dissociated from the ion exchange matrix and eluted. The stronger the protein binding, the greater the salt concentration needed to elute it.

Alfa Chemistry covers the entire process of your protein purification. We focus on solving complex protein components. You only need to put forward ideas and leave the rest to our team. As long as you have any questions about protein purification by ion chromatography, you can consult us. Our customers can directly contact our experts and provide timely feedback on any online inquiries. If you are interested in our services, please contact us.