Emerging solutes from a preparative gel electrophoresis column are drawn into a narrow transfer tube through a collar which fits over the column end and secures a porous plate and dialysis membrane to the column end. The collar is provided with a series of channels running from the collar exterior to a series of locations on its interior wall based around the periphery of the porous plate. An external pump draws lower buffer solution into these channels and laterally through the porous plate to essentially located withdrawal tubing. The solutes emerging from the tubing are then directed to a fraction collector.
A preparative electrophoresis device having a pair of spaced apart plates, a pre-cast electrophoretic gel between the plates, and a semipermeable membrane sealably connected to ends of the plates to define with the plates a collection channel for receiving molecules that have traveled through the gel. Also disclosed are close spacing (less than 2.0 mm) of the plates, an inlet tube and an outlet tube connected to the two plates and communicating with opposite ends of the collection channel, an elongated divider between the plates to divide the gel into a purification region and an indicating region that is not as wide as the purification region and receives marker molecules of known molecular weight to indicate the location in the indicating region of molecules of interest, and pumping electrophoretic buffer into the collection channel at the same rate that it is pumped out.
A novel device and method for biomolecule purification is provided as a handy tool for routine applications when both a high resolution and an easy manipulation are required. A sample is applied into a device and the different biomolecules are separated from each other and stored in segregated liquid fractions in the device automatically after 1 hour electrophoresis. These purified biomolecules in liquid fractions are then easily released from the device in 4 minutes.
A protein purification system employs a pretreatment device which operates in concert with an electrophoretic purification device to separate and retrieve a large volume of highly purified proteins or other products from a mass of crude cellular extract. The pretreatment device causes the products to migrate horizontally through a series of cassettes and chambers at a relatively rapid rate determined by the size of the products to produce a crude mixture of products amenable to further purification. The purification device employs continuous vertical gel electrophoresis to separate the crude mixture into the highly purified products in large volumes and at a high rate without cooling. The electrophoretic purification device is also durable, easy to construct and use, and can be easily adjusted to vary the amount of matrix or gel through which the products must migrate, thus varying the amount of available purification.
A preparative electrophoresis apparatus suitable for recovery of molecules from gels comprises two spaced apart electrode compartments connected by a conduit that descends from the bottom of the electrode compartments in a V-shaped or U-shaped form. The conduit serves as a reservoir for collecting electroeluted molecules. Two electrophoresis buffers are used, a first one of a low concentration and density, and a second one of a high concentration and density. The electrode compartments are filled with the first electrophoresis buffer solution while the conduit is filled with the second electrophoresis buffer solution. Under the influence of an electric field, the molecules exit the gel and concentrate in the high concentration buffer. After a certain time, usually a time that is sufficient for driving substantially all desired molecules out of the gel, the electric field is switched off. The high concentration buffer containing the electroeluted molecules is withdrawn from the conduit. The target molecules may be recovered from the high concentration buffer solution.
The present invention comprises devices and methods for performing channel-less separation of cell particles by dielectrophoresis, DC high voltage-pulsed electronic lysis of separated cells, separation of desired components from crude mixtures such as cell lysates, and/or enzymatic reaction of such lysates, all of which can be conducted on a single bioelectronic chip. A preferred embodiment of the present invention comprises a cartridge (10) including a microfabricated silicon chip (12) on a printed circuit board (14) and a flow cell (16) mounted to the chip (12) to form a flow chamber. The cartridge (10) also includes output pins (22) for electronically connecting the cartridge (10) to an electronic controller. The chip (12) includes a plurality of circular microelectrodes (24) which are preferably coated with a protective permeation layer which prevents direct contact between any electrode and a sample introduced into the flow chamber. The permeation layer also helps to reduce cell adhesion at field minima, and enables immobilization of specific antibodies for specific cell capture. Specific cells from various cell mixtures were separated, lysed, and enzymatically digested on the chip.
