The ElectroPrep system from Harvard Apparatus is an extremely versatile patented sample prep technology based on (2D) electrophoresis/dialysis. This ElectroPrep system is ideal for the rapid purification of proteins, nucleic acids, carbohydrates and other biomolecules.
With a run-time of 5 to 10 minutes, ElectroPrep provides speed and convenience, even at the very low currents (5 to 10 mA) used with this system. The sample chambers are made of Teflon, a completely inert material especially suited for high sample recovery. Membranes of different MWCO (molecular weight cut off), from 100 to 300,000 Daltons, can band membranes).
Electro-Elution of DNA, Proteins or other Biomolecules from Gel Pieces
Using the ElectroPrep system in the illustrated configuration, elution of DNA, proteins, or any other biomolecules from a gel slice/plug can be achieved quickly and easily with excellent recovery. Chambers can be joined in any combination necessary to accommodate the required gel volume. Samples can be concentrated if desired, by choosing a receiving chamber of suitable volume. The MWCO (molecular weight cut off) of the membranes (a and b) can also be chosen to achieve very selective filtration or size fractionation during the electro-elution process.
Selective Electro-Filtration/Concentration/Separation Based on Different Charges on Biomolecules
In this configuration of the ElectroPrep, the sample is placed in a sample compartment between two membranes (b), both of which should have a MWCO larger than the desired biomolecules. Membranes (a) and (c) should have MWCOs smaller than the biomolecules. Based on their charges, the biomolecules will move to either chamber (1) or chamber (2). Biomolecules with unknown isoelectric points can also be separated and purified using this method.
Electrodialysis through Simultaneous Exchange
of Buffers
A sample is placed in the sample compartment between membranes (a) and (b), both of which have MWCOs lower than the molecular weight of the desired biomolecules. The sample is dialyzed through the simultaneous exchange of buffers in the electric field. This method is very fast and very effective. For example, after a PCR reaction, it can be used to rapidly (5 to 10 minutes) remove 100% of the primer. Electrodialysis is also effective for desalting neutral molecules that do not move in an electric field (such as sugars) or charged molecules at their isoelectric point.
Rapid and Selective Electro-Filtration/ Concentration
The sample is placed in the sample compartment comprised of a chamber (1) and the union. The MWCO of membrane (b) should be larger than the molecular weight of the biomolecules and the MWCO of membrane (a) should be smaller. Upon the passage of electric current, the biomolecules will pass through membrane (b) and collect in chamber (2) while smaller molecules will pass through membrane (a). This is a fast and effective method for the concentration of small samples and for selective filtration.