Instrument for independent electrotransfer in multiple cassettes
Electrotransfer is performed in an instrument that receives electroblotting cassettes and that contains an integrated power supply, controls, and a display that allows the user to monitor and control each of a plurality of cassettes individually through electrical contacts within the housing that mate with corresponding electrical contacts on the cassettes.
1. An electrotransfer instrument comprising:
a housing with an internal cavity sized to contain a horizontally oriented electroblotting cassette, said cavity mating with ridges on the side of said cassette;
a power supply and printed circuit board mounted to and within said housing and individual electrical contacts mounted to the interior of said housing for connecting said power supply via the electrical contacts to electrodes in said cassette that is inserted therein; and
a touch screen display for independently monitoring and controlling an electrotransfer procedure in said cassette inserted in said housing.
2. The electrotransfer instrument of claim 1 wherein said housing comprises a front opening for sliding entry of said cassette.
3. The electrotransfer instrument of claim 1 wherein said housing comprises magnetic contacts to secure said cassette within said internal cavity.
4. The electrotransfer instrument of claim 1 further comprising an electrical relay that will engage said electrical contacts with said power source only when a cassette is inserted in said housing.
5. The electrotransfer instrument of claim 1 wherein said cassette further comprises a gel, a membrane, and buffer-wetted filter papers arranged in a stack.
6. The electrotransfer instrument of claim 5 wherein said cassette further comprises plate electrodes arranged in a stack, which are connected to said electrical contacts.
7. The electrotransfer instrument of claim 1 wherein said individual electrical contacts are spring-loaded electrical contacts.
8. The electrotransfer instrument of claim 1 , further comprising grooves in the internal surfaces of the side walls of the cavity, wherein the grooves mate with ridges on the side of the cassette and align the cassette with the electrical contacts.
9. A method for transferring electrophoretically separated species from a slab gel to a sheet-form matrix, said method comprising:
(a) placing said slab gel and a sheet-form matrix in an electroblotting cassette that comprises anode and cathode plates and external electrical contacts for each of said plates;
(b) inserting said cassette in the electrotransfer instrument of claim 1 such that said external electrical contacts are in contact with said individual electrical contacts; and
(c) imposing electrical charges on said electrodes to cause said species to migrate electrophoretically from said slab gel to said sheet-form matrix within said inserted cassette.