Principle of Gradient Ethanol Precipitation (GEP)

GEP is an effective approach for isolating products from complex mixtures such as plant extracts or fermentation broths. It involves the gradual addition of alcohol to the polysaccharide-containing solution, resulting in the polysaccharide gradually precipitating. Ethanol can change the polarity and properties of the solution, allowing polysaccharides to exhibit different solubility in different concentrations of ethanol. Polysaccharides are purified and enriched by precipitating them from the solution by gradually increasing the ethanol concentration. It utilizes a gradient in alcohol concentration to selectively precipitate the polysaccharide while other impurities remain in the solution. By centrifugation, the precipitated polysaccharides can be separated and collected for further processing. This method presents the advantages of simplicity of operation, low cost, and scalability. The target polysaccharides are effectively isolated and purified from complex mixed samples by this method, which helps to promote a further study of the properties of the polysaccharides.

Fig.1 A schematic flow diagram for GEP of polysaccharides. (Fernando, et al., 2020)

GEP-based Polysaccharide Purification Service at CD BioGlyco

CD BioGlyco focuses on the optimization of the glycan purification process and follows strict quality control standards to ensure product stability and consistency. By choosing our polysaccharide purification service, clients will obtain high-quality polysaccharide products that will add value to their business. The process of our purification service is as follows:

• Sample and Gradient Ethanol Preparation

Collection of solutions or extracts containing polysaccharides as initial samples. A series of solutions with progressively increasing concentrations of ethanol are prepared according to the desired precipitation effect. We commonly prepare a gradient based on water with the gradual addition of different volume ratios of ethanol.

• Purification Process

Gradually adding a gradient ethanol buffer to the sample, either in a top-down or bottom-up way, creates a gradient of increasing ethanol concentration. The mixture is allowed to stand for several hours so that the polysaccharides gradually precipitate in the different concentrations of ethanol solution. During this process, the polysaccharides form complexes with ethanol and gradually aggregate into precipitates.

• Separation and Washing

The gradient ethanol solution is centrifuged using a centrifuge to allow the product to settle to the bottom of the centrifuge tube. The product precipitate obtained after centrifugation is collected and residual ethanol and impurities are removed using a detergent or other solution.

Fig.2 Applications of GEP. (CD BioGlyco)

Applications

• Polysaccharide purification techniques can be used to obtain pure polysaccharide samples for in-depth studies of their structure and functions.
• Polysaccharide purification techniques are commonly used to purify and extract natural polysaccharides or synthetic polysaccharide compounds in the drug discovery process. The purified samples are also commonly used in the development and optimization of drug formulations.
• Polysaccharides have a wide range of applications in the food industry, such as thickeners, stabilizers, emulsifiers, etc.

Advantages of Us

• The solubility of polysaccharides and other components varies with different concentrations of ethanol, allowing selective enrichment or removal of target polysaccharides. This controllability allows for a high degree of flexibility and precision in the purification process.
• We provide one-stop polysaccharide purification services to help our clients save time and effort and devote more resources to core research and development.

CD BioGlyco provides our clients with ideal and customized experimental designs. Our services are not limited only to GEP-based Polysaccharide Purification Services, but we also provide Polysaccharide Manufacturing services, including Starch Manufacturing Service and Glucan Manufacturing Services. If you are interested in our services, please contact us for more details.

• Salt Fractionation-based Polysaccharide Purification Service
• Chromatography-based Polysaccharide Purification Service