Development of device and methods to concentrate, separate and characterize low-abundance proteins with high resolution for diagnostic detection of trace biomarkers and treatment of economically important human diseases has always been desired. Commercially available, polyacrylamide gel electrophoresis (PAGE), has been the widely used tool for protein separations, but this technique has multiple downsides: long separation time, large amount of sample required, low reproducibility, breakdown under high electric field, and low dynamic range.
A number of separation platforms, including microfluidic, and nanofluidic channel devices, have emerged to overcome PAGE’s limitations. Despite recent advances in nanofluidic technologies, there exist no systems and methods that provide high-resolution focusing and separation of proteins using nanofluid channels. This is the first invention that provides a versatile platform to separate proteins with high resolution, using different separation techniques: isoelectric focusing (IEF) and dynamic field gradient focusing (DFGF). This invention offers to establish a stable pH gradient without the use of ampholytes by utilizing transverse gate electrodes to manipulate the surface charge and therefore zeta potential of the channel walls. pH in the nanochannels can be manipulated enabling use of several protein separation techniques.
Applications and Advantages
§ Cost effective and efficient;
§ High resolution protein focusing;
§ Does not use ampholytes;
§ Requires low electrical potential and short separation time;
§ Requires small amount of sample for analysis; and
§ Offers greater reproducibility than conventional methods.
US patent and PCT applications pending