VERTICAL SLAB TYPE ELECTROPHORESIS APPARATUS

Abstract: A novel vertical slab type electrophoresis apparatus, characterized by the provision of a gel holding glass sheet couple detachably fitted in a pair of tapered fitting groove formed opposingly on and along the entire length of glass support column portions of a buffer solution chamber by means of wedge-like fixing bars having an outer shape corresponding to the internal wall shape of said fiiting groove. The elecrophoresis apparatus precludes distortion of the gel which is gripped between the coupled glass sheets, permitting to obtain excellent migration images while preventing fracture of the glass sheets.

Description: BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to a vertical slab type electrophoresis apparatus, and more particularly to a vertical slab type electrophoresis apparatus which is capable of fixedly holding a gel holding glass sheet couple with uniform force and in a facilitated manner. 2. Description of the Prior Art The vertical slab gel electrophoresis system which is superior to the disk type electrophoresis system in operationability and resolution and which is capable of two-dimensional development is frequently used these days as a means suitable for separation and analysis of biological components such as proteins, nucleic acid and the like. The conventional apparatus employed for such electrophoresis processes usually have a gel holding glass sheet couple connected to a buffer liquid chamber by fixing the opposite sides of the glass sheets to support column portions by the use of clips l0 or screws by fixing arbitrary points by the means of wedges (Fig. 10). However, electrophoresis apparatus with such fixing means are found to be unsatisfactory because of the problems arising from uneven force of retention and fixation, e.g. distortion of gels, deterioration of migration images and fracture of glass sheets. SUMMARY OF THE INVENTION The present inventors have conducted an intensive study in search for a solution to the above-­ mentioned problems, and as a result found that the migration image can be improved to a marked degree by fixing the paired gel holding glass sheets with uniform force by the means of tapered fitting groove in combination with wedge-like fixing bars. More particularly, in accordance with the present invention, there is provided a vertical slab type electro phoresis apparatus including a gel holding glass shett couple, characterized in that the apparatus comprises; a pair of tapered fitting groove formed opposingly on and along the entire length of glass support column portions of a liquid buffer chamber for receiving the opposite sides of the couple of gel holding glass sheets; and wedge-like fixing bars having an outer shape corresponding to the inner wall shape of the glass fitting groove and engageable in the fitting groove to fix the glass sheets detachably therein. BRIEF DESCRIPTION OF THE DRAWINGS Fig. l is a perspective view of an electrophoresis apparatus embodying the present invention, with horizontally juxtaposed buffer liquid chamber; Fig. 2 is a perspective view of an electrophoresis apparatus embodying the present invention, with vertically juxtaposed buffer liquid chambers; Fig. 3 is an enlarged sectional view employed for the explanation of the manner of holding and fixing a glass sheet couple; Fig. 4 is a perspective view of an embodiment of the glass support column portions; Fig. 5 to 7 are perspective views showing in separated state the glass support column portions and wedge-like fixing bars of modified constructions; Figs. 8 and 9 are perspective views showing in separated state the glass sheet couple and packing; and Fig. l0 (PRIOR ART) is a perspective view of a conventional electrophoresis apparatus. DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS Hereafter, the invention is described more particularly by way of preferred embodiments shown in the drawings. In the various figures, indicated at l is a gel holding glass sheet couple for grippingly holding a migration gel between two glass sheets. This gel holding glass couple may be constructed in an arbitrary form, for example, may be constituted by; a pair of glass sheets la and lb which are bonded to each other through spacers lc, one glass sheet la having an indented upper edge while the other glass sheet lb is provided with a straight upper edge (Fig. 8); or a pair of straight-edged glass sheets ld of different heights or lengths, which are bonded to each other through spacers lc in such a manner that the upper edge of one glass sheet falls short of the other glass sheet (Fig. 9). The reference numeral 2 denotes a chamber of a buffer liquid trough which may be of the type having inner and outer chambers or of the type having upper and lower chambers. Indicated at 3 are glass support column portions which are formed in suitable positions depending upon the shape of the buffer liquid chamber. The glass support column portions 3 are provided with tapered fitting groove 4 for receiving therein the glass sheet couple l and wedge-like fixing bars as will be described hereinlater, the fitting groove 4 being formed opposingly and tapered along the entire length of the glass support column portions 3. The tapered fitting groove 4 is broadened toward an opening through which the wedge-like fixing bar is inserted, for instance, toward the upper side (Figs. 4 and 6), toward the lower side (Fig. 7) or toward the lateral side (Fig. 5). Designated at 5 are the wedge-like fixing bar which have an outer shape corresponding to the inner wall shape of the glass fitting groove 4, and inserted into the latter after fitting the opposite side of the gel holding glass sheet couple l in the groove 4, thereby detechably fixing the glass sheet couple l in the groove 4. For fixation of the gel holding glass sheet couple l, it is desirable to provide packing 6 between the glass sheet couple l and the inner wall surface of the fitting groove 4. For this purpose, the glass fitting groove 4 are preferably provided with groove 4l on the inner wall surfaces for receiving the packing 6. With the apparatus of the invention as described above, the gel holding glass sheet couple is fixedly retained in the glass fitting groove on the glass support columns of the liquid buffer chamber by the wedge-like fixing bars, so that substantially uniform pressure is exerted on the glass sheet couple as a whole. Accordingly, the electrophoresis apparatus of the invention precludes distoration of the gel which is gripped between the coupled glass sheets, permitting to obtain excellent migration images while preventing fracture of the glass sheets. Besides, in case of the electrophoresis apparatus shown in Fig. l as an exemplary embodiment of the invention, it is possible to increase the height of the outer buffer liquid chamber 2l and cool the gel holding glass sheet couple from both of the inner and outer buffer liquid chambers 22 and 2l, allowing to conduct the electrophoresis with higher voltage and current as compared with conventioal counterparts. For example, electrophoresis for a l0 × 8.6 × 0.l cm SDS-­ polyacrylaminde gel using 3 mm thick glass sheets can be conducted with a voltage and a current as high as 500 V and 60 mA, respectively, in a shortened migration time of about 30 minutes without a smile phenomenon of the migration image. When packing is used in combination with the glass sheet couple as shown in Fig. 9, it becomes possible to employ higher voltage (800 V) and current (l000 mA) for the electrophoresis thereby to shorten the migration time and obtain an improved migration image free of the smile phenomenon.

Claims: 1. A vertical slab type electrophoresis apparatus, characterized by the provision of a gel holding glass sheet couple detachably fitted in a pair of tapered fitting groove formed opposingly on and along the entire length of glass support column portions of a buffer solution chamber by means of wedge-like fixing bars having an outer shape corresponding to the internal wall shape of said fitting groove.

Inventors: EBATA, NOBUYOSHI, HIRATA, MIYOSHI, SUGIMURA, YOSHIO, TERAMURA, YUMI
Applicants: DAIICHI PURE CHEMICALS CO. LTD.
Application year: 1986
Main classification: G01N27
IPC codes: B01D57, C12M1, G01N27