Abstract:
A gel tray to be inserted into an electrophoresis trough having stop members and a stop plate as well as engaging members to securely abut the plate to the trough body. This feature allows for leak free gel casting. To adapt for electrophoresis, just remove the stop members for a fast and convenient way to consolidate steps when compared to conventional techniques.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to improvement of the structure of gel tray of a horizontal electrophoresis trough used for biologic experiments, and especially to an improved gel tray which renders the process of consolidation of gel fast and convenient against the defects of having the necessity to repeat manufacturing processes resided in conventional techniques. 
     Horizontal electrophoresis troughs are designed for separation and analysis in DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) in biotechnology, this is based on the principle that electric current drives molecules to move in gel formed from a kind of porous material, and the DNA and RNA are separated by difference of the electric load of the ionic elements and sizes of the molecules respectively of the DNA and RNA themselves. This occupies an extreme important position in the application of the basic theory of biotechnology. 
     As shown in FIG. 1, an electrophoresis trough is comprised mainly of an upper lid A, a lower trough body B and a gel tray C, wherein, the upper lid A and the lower trough body B are provided on the front and rear ends thereof with electrode members, the lower trough body B is in the form of a vessel to receive therein buffer solution for an experiment, a platform B 1  is provided centrally of the lower trough body B to support the gel tray C. Two walls are provided laterally of the gel tray C which is opened on the front and rear sides thereof. When the gel tray C is provided therein with pre-consolidated gel D, and a solution sample for analysis and test is placed in a sample hole on the gel D in the lower trough body B, then the electrode members are electrically connected to drive the molecules in the sample from the negative electrode toward the positive electrode, in order to separate molecules of different natures. 
     In the above process, the liquid gel D must be consolidated into a porous solid state in advance for proceeding of the experiment, and the front and rear sides of the pre-consolidated gel D must be kept plane in order to get correct conclusion of the experiment. Therefore, the preference conditions for analysis and test of the experiment are to find a way to consolidate the gel in the gel tray and to keep it intact in the electrophoresis trough. 
     2. Description of the Prior Art 
     A method for consolidation of gel in the early period was to use sterilized tapes to seal the opened front and rear ends of a gel tray C, and then to cast liquid gel therein; the sterilized tapes were torn off after consolidation of the gel. 
     Such method using sterilized tapes is simple and convenient, however, it is disadvantageous in that sterilized tapes are soft tapes, pressure created by the cast liquid gel will spread the sterilized tapes outwardly to form arciform rims on the solidified gel and to make leakage at the gaps resulted at the junctions of the sterilized tapes and the gel tray. Thereby, rough edges are generated at the front and rear ends of the consolidated gel, this influences quality of samples in the experiment, an operator even needs to repeat for several times or makes once for all many spare consolidated gels in order to get a gel perfectly manufactured. This is time and spirit consumptive. Besides, the gel leakage by capillarity will make untidy of the table surface in a lab. And more, the sterilized tapes are discarded after use; they cannot be repeatedly used and thus are uneconomic. 
     As shown in FIG. 2 which shows a second conventional method, wherein, the gel tray C is directly placed under the platform B 1  of the lower trough body B, and the lower trough body B is provided at the locations on the lateral sides thereof near by the front and rear ends of the gel tray C with a plurality of vertical “V” shaped grooves E for inserting therein stop plates F. The stop plates F form barrels inside of the front and rear ends of the gel tray C. Thereby, after consolidation of the cast liquid gel, the stop plates F can be removed, and manufacturing of the gel can be completed. 
     Such method has the advantage that after removing of the stop plates F, if the consolidated gel is perfect, it can be used directly for the experiment, and can be repeatedly used. However, it has the disadvantages that, tightness of closing of the stop plates F and the grooves E is insufficient, leakage still exists; and consolidation of the cast liquid gel directly in the lower trough body B results inability of making many spare consolidated gels (unless there are many expensive electrophoresis troughs). If the gel is damaged, it must be manufactured again from the beginning and must wait again for consolidation; this is troublesome and time consuming. And more, after consolidation, the rims of the consolidated gels will be attached to the stop plates F; hence when the stop plates F are removed by lifting upwardly, the consolidated gels may be damaged. Further, by the fact that the objects for the gel tray C in the experiment may be varied, widths of the front and rear ends of the gel tray C include at least two kinds, each gel tray C can only be used for a specific electrophoresis trough, i.e., at least two electrophoresis troughs of different specifications must be provided for a lab, this is surely uneconomic. 
     As shown in FIGS. 3 and 4, they show a third known technique, wherein, an auxiliary seat G is used to assist a gel tray C for gel consolidation, the auxiliary seat G is comprised of a base G 1 , a movable front stop plate G 2  and a fixed rear stop plate G 3 . The gel tray C is placed on the base G 1  with the rear end thereof being abutted against the fixed rear stop plate G 3 . Now the movable front stop plate G 2  can be adjusted horizontally to close to the front end of the gel tray C, a rotary knob G 4  can be screwed tight and then the front and rear ends of the gel tray C are sealed in order to proceed gel consolidation. The rotary knob G 4  is unscrewed after gel consolidation to allow moving outwardly of the movable front stop plate G 2 , thus manufacturing is completed. 
     Such method using the auxiliary seat G to assist the gel tray C has a defect of being more trouble in operation, and cost of the auxiliary seat G is more expensive. While it is quite safe to release the consolidated gel by moving outwardly of the movable front stop plate G 2  without damaging the consolidated gel, this can be an important reference. 
     As shown in FIG. 5 which shows a fourth conventional method, wherein, a gel tray C is directly placed in a container H, the gel tray C is sealed by surrounding plates H 1 , liquid gel D is cast into the gel tray C and is consolidated, then the gel tray C can be taken out. Such a conventional structure can be very convenient for use; however, it has the same defect as that of the structure shown in FIG. 2, i.e., the consolidated gel D is subjected to damage. 
     SUMMARY OF THE INVENTION 
     The inventor of the present invention developed the improved structure of gel tray for an electrophoresis trough based on his specific experience of years in manufacturing as well as selling biologic experimental instruments and after synthesizing the advantages and disadvantages of the conventional techniques. With this structure, the gel tray can complete gel consolidation faster, more convenient and more economic. 
     In particular, the gel tray of the present invention is comprised mainly of a body and a front and a rear stop member, wherein, the body can be placed in an electrophoresis trough. Two side wall-plates on the bottom plane plate of the gel tray are extended vertically upwardly and provided with a plurality of recesses; the front and rear ends of the bottom plane plate are opened. The above stated stop members are further respectively provided with a stop plate, and are respectively assembled together with an engaging member and a lever latch. When the front and rear stop members are respectively placed on the front and rear ends of the tray body with the stop plates thereon, they can be engaged in the recesses on the side wall-plates by moving the lever latches on the engaging members. So that the stop plates tightly abut against the front and rear ends of the tray body, the surrounding walls of the tray body thus are formed in a sealing state for casting therein liquid gel. After consolidation of the gel, the tray body can be released from engaging of the side wall-plates again by moving of the lever latches to move the engaging members. The stop members thereby can be detached without damaging the front and rear end surfaces of the consolidated gel. 
     The present invention has the following advantages structurally: 
     1. Mounting and detaching of the front and rear stop members are very fast and convenient; they are operationally easy and convenient for use. 
     2. When in detaching the stop members after consolidation of the gel, the stop plates are moved away from the gel horizontally, thereby, the front and rear end surfaces of the consolidated gel will not be damaged. 
     3. The front and rear stop members of the present invention can suit gel trays of various widths, there is no need to purchase another electrophoresis trough to suit another gel tray. 
     4. Cost of production of the stop members is inexpensive; a user is not necessarily to purchase them with overly expensive prices. 
     The present invention will be apparent in its particular structure and function after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an analytic perspective view of an electrophoresis trough and a gel tray; 
     FIG. 2 is an analytic perspective view showing consolidation of gel in the electrophoresis trough mounted with stop plates; 
     FIG. 3 is a perspective view showing a conventional gel tray on an assisting auxiliary seat; 
     FIG. 4 is a perspective views showing the conventional gel tray with an assisting auxiliary seat is used for consolidation of gel; 
     FIG. 5 is an analytic perspective view showing a gel tray and a container in a conventional technique are under the process of consolidation of gel; 
     FIG. 6 is an analytic perspective view of a gel tray of the present invention; 
     FIG. 7 is a partially enlarged perspective view of FIG. 5; 
     FIG. 8 is a top view showing the tray body and stop members of the gel tray of the present invention before being assembled; 
     FIG. 9 is a schematic view showing assembling of the tray body and the stop members of the gel tray of the present invention; 
     FIG. 10 is another schematic view showing assembling of the tray body and the stop members of the gel tray of the present invention; 
     FIG. 11 is a top view showing completing of assembling of the tray body and the stop members of the gel tray of the present invention; 
     FIG. 12 is a side sectional view showing completing of assembling of the tray body and the stop members of the gel tray of the present invention; 
     FIG. 13 shows another embodiment of a leakage-proof cushion of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring firstly to FIGS. 6 and 7, the gel tray of the electrophoresis trough of the present invention is comprised structurally mainly of a tray body  10  and a front and a rear stop member  20 . 
     Wherein, the tray body  10  can be placed in the electrophoresis trough. Two side wall-plates  12  on a bottom plane plate  11  of the tray body  10  are extended vertically upwardly and are provided with a plurality of recesses  13 , the front and rear ends of the bottom plane plate  11  are opened. 
     The stop members  20  are further provided each with a stop plate  21 , and with an engaging member  22  and a lever latch  23  respectively assembled on one side and the other side thereof. When the front and rear stop members  20  are respectively placed on the front and rear ends of the tray body  10  with the stop plates  21  thereon, the surrounding walls of the tray body  10  thus are formed in a sealing state, hooks  222  provided on the engaging members  22  can be engaged in the recesses  13  on the side wall-plate  12  by moving the lever latches  23  on the engaging members  22 . So that the stop plates  21  tightly abut against the front and rear ends of the tray body  10  for casting therein liquid gel. After consolidation of the gel, the tray body  10  can be released from engaging of the side wall-plates  12  again by moving of the lever latches  23  to move the engaging members  22 . The stop members  20  thereby can be detached without damaging the front and rear end surfaces of the consolidated gel. 
     Referring to FIG. 7, the structure features of the stop plates  21 , the engaging members  22  and the lever latches  23  of the stop members are as below: 
     The stop plates  21  are straight and plane, and are provided each on the inner side thereof facing to the front and rear ends respectively of the tray body with a leakage-proof elastic rubber cushion  211 . The stop plates  21  are provided each on both ends thereof with a connecting piece  212  having a bending end, the connecting piece  212  is provided on the top and bottom thereof each with a protruding point  213 . 
     The engaging members  22  each is mounted on the connecting piece  212  of a stop plate  21  and is provided on one end thereof with a notch  221  and on the other end thereof with a hook  222 . Wherein, the notch  221  is to clamp on the connecting piece  212  in contact with the protruding points  213  of the connecting piece  212 . The engaging members  22  each is further provided with a guide groove  223  for insertion of the protruding points  213 . The guide groove  223  includes two sections, one is straight; the other is arciform. When the engaging member  22  is connected to a connecting piece  212 , the guide groove  223  slides on the protruding points  213  to allow the connecting piece  212  to move to and fro or in a mode of swaying in an arc. And a pivot connecting seat  224  is provided just outside of the notch  221 . 
     The lever latches  23  each has a pivot axle  231  for connecting to the pivot connecting seat  224  of the engaging member  22 , in order that the lever latch  23  can be swiveled about the pivot connecting seat  224 . The lever latch  23  has a pushing panel  232  corresponding in operation to the bending end on the connecting piece  212 . 
     Referring to FIG. 8 which is a top view showing the tray body  10  and the stop members  20  on the gel tray of the present invention before being assembled, wherein, the stop members  20  are respectively placed on the front and rear ends of the tray body  10 , the stop plates  21  of the stop members  20  are located now respectively at the front and rear ends of the tray body  10 , the engaging members  22  at both sides of each of the stop plates  21  are in the state of opening outwardly, and the lever latches  23  has not moved the engaging members  22  yet. 
     Referring to FIG. 9 which is a schematic view showing assembling of the tray body  10  and the stop members  20  of the gel tray of the present invention, wherein, the stop plates  21  of the stop members  20  at the front and rear ends are abutted respectively against the front and rear ends of the tray body  10 , the surrounding walls of the tray body  10  thus are formed in a sealing state. Then the engaging members  22  are moved toward the two side wall-plates  12  of the tray body  10  each in a mode of displacement in an arciform path to make hooks  222  on the engaging members  22  engaged in the recesses  13  on the side wall-plates  12 . Moving of the engaging members  22  in arciform paths can be effected by cooperation of the guide groove  223  with the protruding points  213 . 
     Referring to FIG. 10 which is another schematic view showing assembling of the tray body  10  and the stop members  20  of the gel tray of the present invention, wherein, after the hooks  222  on the engaging members  22  are placed into the recesses  13  on the side wall-plates  12 , the lever latches  23  are moved to swivel about the pivot connecting seat  224 , the pushing panels  232  of the lever latches  23  are abutted against the bending ends on the connecting pieces  212  to exert an action force to move the engaging members  22  and the hooks  222  downwardly in the drawing to make them slide. During sliding, the protruding points  213  are located in the straight sections of the guide grooves  223 , so that the engaging members  22  and the hooks  222  thereof slide downwardly in a straight line. 
     Referring to FIG. 11 which is a top view showing completing of assembling of the tray body and the stop members, wherein, before the lever latches  23  are moved to the terminal positions of their strokes, the hooks  222  on the engaging members  22  are moved downwardly and are abutted against the recesses  13  on the side wall-plates  12 , thereby the stop plates  21  get close to the tray body  10  and press the latter. When the lever latches  23  are moved to the terminal positions of their strokes, the leakage-proof cushions  211  of the stop plates  21  provided with elasticity are tightly abutted against the front and rear ends of the tray body  10  and the side wall-plates  12 , so that the surrounding walls of the tray body  10  are formed in a sealing state for casting therein liquid gel for consolidation. No liquid gel will leak out. 
     Summarily, from the above structural connecting relationship of the present invention stated in reference to FIGS. 6 to  11 , when a user assembles the tray body  10  and the stop members  20 , the stop members need only to be placed respectively on the front and rear ends of the tray body  10  (only the front end is shown in the drawings by virtue that the front and rear ends are identical to each other only with opposite orientations mutually) to make the stop plates  21  block the front and rear ends of the tray body  10 , then the engaging members  22  and the hooks  222  abut against the recesses  13  on the side wall-plates  12 , and move the lever latches  23  to make the stop plates  21  tightly abut against the ends of the tray body  10  to complete connection. This is very convenient and quick in operation. 
     One thing worth mentioning, after consolidation of the liquid gel in the tray body  10 , and when it is to detach the stop members  20  to proceed the experiment, the leakage-proof cushions  211  provided with elasticity and abutted tightly against the tray body  10  and the side wall-plates  12  will give an elastic force, by moving the lever latches  23  to release the hooks  222  on the engaging members  22  from the recesses  13 , to move the stop plates  21  away from the tray body  10  outwardly. Thereby, the stop plates  21  during detachment will not abrade the consolidated gel, and the front and rear end surfaces of the consolidated gel can be kept intact. 
     And more, in practicing the present invention and in order to make abutment of the leakage-proof cushions  211  against the tray body  10  more tight, the bottom areas of the front and rear ends of the tray body  10  in contacting with the leakage-proof cushions  211  can be provided with recessed portions  14  (as shown in FIG.  12 ). When the leakage-proof cushions  211  which are made of rubber are abutted tightly against the front and rear ends of the tray body  10 , the lower portions of the leakage-proof cushions  211  will be extruded to protrude slightly (as shown in FIG. 12 too). In this way, the leakage-proof cushions  211  will be abutted against the tray body  10  more tight to prevent the liquid gel cast in the tray body  10  from leaking out. 
     Further, to prevent plastic deformation of the areas of the leakage-proof cushions  211  abutting against the tray body  10  after being long used, in practice, the leakage-proof cushions  211  can leave, at the contact areas of them with the bottom plane plate  11  of the tray body  10  and the side wall-plates  12 , “U” shaped slits  214  having three sides with widths equal to the thickness of the bottom plane plate  11  of the tray body  10  and the side wall-plates  12  respectively. Thereby, when in engaging of the slits  214 (as shown in FIG. 13) with the tray body  10  and the side wall-plates  12 , not only the leakage-proof cushions  211  can be prevented from deformation, but also an enhanced sealing effect can be obtained. 
     The names of the members composing the present invention and the shape shown in the drawings are only for illustrating a preferred embodiment of the present invention, and not for giving any limitation to the scope of the present invention. It will be apparent to those skilled in this art that various equivalent modifications or changes can be made to the elements of the present invention without departing from the spirit, scope and characteristic of this invention. Accordingly, all such modifications and changes also fall within the scope of the appended claims and are intended to form part of this invention.