Home |  News |  Events |  Publications |  Contact 
Investor LifeScience Diagnostics Technology Career
Gradiflow Technology
Gradiflow Technology  
Gradiflow Technology
Gradiflow is a unique membrane-based separation technology that allows molecules of interest to be isolated with high purity and yield.

How Does Gradiflow Work?

The Gradiflow is an electrophoresis instrument which has two circulating streams, Stream 1 and Stream 2. The two streams are separated by a separation membrane and confined by restriction membranes. In an electric field a molecule will move towards the electrode of opposing charge. The electrodes are positioned so that Stream 1 contains molecules with a positive charge and Stream 2 molecules which are negatively charged. Charged molecules can be moved between the streams when a current is applied. This allows the separation of specific molecules from a complex mixture.
Using the Gradiflow molecules can be separated by charge and size.

Charge Based Separation

Molecules such as proteins have different charges depending on the pH of the solution. If the pH is close to the isoelectric point (pI) of the protein it will have little charge and small movement under an electric field. Two molecules with different pIs may be separated on the Gradiflow by performing a separation at a pH between the two pI values. This causes one molecule to have a net positive charge and the other molecule a net negative charge. In the example on the right, the positively charged molecules are attracted towards the negative electrode and remain in Stream 1. The negatively charged molecules migrate towards the positive electrode through the separation membrane and into Stream 2.

Size Based Separation

Size separations are performed on the Gradiflow by using separation membranes with different pore sizes. In the example on the right, a high pH buffer is used, imparting a net negative charge on all of the molecules. The larger negatively charged molecules are unable to migrate through the separation membrane due to size constraint and are maintained in Stream 1. The small negatively charged molecules are able to migrate through the separation membrane towards the positive electrode and are contained in Stream 2.


Want to see how it works? Check out our animations!
Click on the downloadable QuickTime movie files on this page. It may take a few minutes to download (depending upon your connection).

You will need QuickTime viewer to see the animation. If you don't have QuickTime viewer, download your free copy by clicking here.

Click here to download our brochure on Protein Purificaton!

128915k -
124915k -
Contact Us | Terms of Use | | Terms of Use
2002 Gradipore Limited All rights reserved.