1. Λπ electrophoresis apparatus adapted to be used for analytical and preparative purposes, having two electrode ch .a fitted each with one electrode, and a matrix compartment by wh said chambers coirjvanica e with each other, characterised by a disasse.Tibable cell unit which comprises a trough-like portion adapted to hold a liquid body "and to serve as a first electrod chamber and in communication therewith a panel shaped portion serving as matrix compartment , which cell i3 adapted for remov therefrom the matrix in the disassembled! state ; and by a casing serving aa a second electrode chamber, which casing is adapted to accomodate said cell unit ond to hold a liquid body such t the matrix compartment of the cell unit is substantially submerged, the volume of said liquid body being at least ten time the volume of the matrix compartment · 2. An apparatus according to Claim 1 comprising agitati means in the second electrode chamber. j$. An apparatus according to Claim 1 or 2 so adapted th in the preparative application means are provided near the edge of the matrix compartment opposite the first electroJe chamber for the eluticn of naterlal arriving by electrophoretl migration. 4. An apparatus according to any one of the preceding Claims so adapted that in the operational state theJ matrix in the matrix compartment bears on a liquid permeable solid body. 5. An apparatus according to Claim 4, wherein said solid body is a gel of a consistency which makes it impermeable to the electrophorized material. 6» An apparatus according to Claim 4, wherein said solid body is a gel of a consistency which makes it selectively permeable to the electrophorized material. 7. An apparatus according to Claim 4, wherein said solid body is porous. 8. An apparatus according to any one of Claims 5 to 7 so adapted that in the preparative application an elution channel is provided at or near the interface region between the matrix r and said solid body, means being provided for flushing said channel thereby to elute material arriving from the matrix by electrophoretic migration. 9. An apparatus according to Claim 8, wherein said solid body is a gel of a consistency which makes it impermeable or means selectively permeable to the electrophorized material,/being provided for the supply of elution liquid at one end .of said elution channel and its withdrawal from the opposite end thereof. 10. An apparatus according to Claim 8, wherein said solid body is porous, means being provided for the withdrawal of liquid from said elution channel, the supply of liquid to the channel occurring automatically by penetration of -liquid from the second electrode chamber into said porous body. 11. An apparatus according to Claim 7 comprising drainage means near the bottom of said porous body which in the preparative application are connected to pumping means thereby to elute the material arriving from the matrix by electrophoretic migration, the supply of liquid for the drainage occurring automatically by 1 2 . An apparatus according to any one of the preceding Claims, wherein said matrix compartment ic flat, 1 3 . An apparatus according to any one of Claims 1 to 1 1 , wherein said matrix compartment is corrugated. 14 An apparatus according to any one of Claims 1 to 11, wherein said matrix compartment is vaulted. 15· An apparatus according to any one of Cluimi- 1 to 11. wherein said matrix compartment is tubular, 16. An apparatus according to any one of the preceding Claims, wherein the matrix compartment depends vertically from the first electrode chamber. 17· An apparatus according to any one of Claims 1 to 1 , wherein the matrix compartment is connected obliquely to the first electrode chamber. 18, An apparatus according to Claim 17, wherein the cell comprises an auxiliary compartment branching off from the matrix compartment. 19» An apparatus according to any one of Claims 1 to 1 5 , wherein the matrix compartment is positioned horizontally in the second electrode chamber and is connected to the first electrode chamber in such a way that at least a portion of the latter merges above the surface of the liquid body in the second electrode chamber. 20. For use in an electrophoresis apparatus according to any one of the preceding Claims, a disassembable cell unit which comprises a trough-like portion adapted to hold a liquid body and to serve in the apparatus as a first electrode chamber, and in communication therewith a panel shaped portion serving as 21 · A cell unit according to Claim 20, wherein the matrix Λ compartment is flat. 22. A cell unit according to Claim 20, wherein the matrix compartment is corrugated. 23. A cell unit according to Claim 20, wherein the matrix compartment ia vaulted. 24. A cell unit according to Claim 20, wherein the matrix compartment is tubular. 25. A cell unit according to any one of Claims 20 to 24» wherein the matrix compartment depends vertically from the trough-like portion. 26. A cell unit according to any one of Claims 20 to 24* wherein the matrix compartment is connected obliquely to the trough-like portion. 27. A cell unit according to Claim 26 comprising an auxiliary compartment branching off from the matrix compartment. 28. A cell unit according to any one of Claims 20 to 24, wherein the matrix compartment is connected to the trough-like portion in such a way that in the assembled apparatus the matrix compartment is positioned horizontally in the second electrode chamber and at least a part of the trough-like portion forming the first electrode chamber merges above the surface of the liquid body in the second electrode chamber. 29. An electrophoresis apparatus substantially as described hereinbefore with reference to the annexed drawings. r · - 28 - <~T' V 30· For use in an electrophoresis apparatus a cell unit substantially as described hereinbefore with reference to Figs. 1 to 9. 12, 13 and 17 to 24· C:mz