The Labnet Gel XL Plus Electrophoresis System is used in our laboratory to run mini-gel electrophoresis. The system comes with all components necessary for casting and running both agarose and acrylamide gels, but we only use it to run agarose gels to check DNA construction. This kit includes a casting set, gel box with safety lid, and a direct-connect power supply. One great feature of this system is that up to 6 gels can be poured at once; unused gels can be conveniently stored in the refrigerator. The casting stand accepts both large (106 x 58 mm) and small (51 x 58 mm) gel trays. The supplied dual format combs have two sets of teeth for forming two different sizes of wells. The gel covers are supplied for use when pouring acrylamide gels. The extra long gel casting set allows for pouring individual agarose gels. The gel box and lid fit together by means of a mechanical interlock. The direct-connect power supply fits into this interlock, preventing the lid from being opened during operation. This attachment of power supply does away with the use of leads and ensures the power supply is connected properly all the time. This system is also designed to be leak proof.
This unit is relatively small and compact, measuring 116 x 44 x 56 mm (L x W x H). This gel casting system has the capacity for 2 large and 4 small gel trays. The gel casting set consists of the gel casting stand, gel trays, and dual format combs. The combs are delicate; it would be nice if they were sturdier. The stand can accommodate up to 6 gels (4 small and 2 large gels) at the same time. The stand can also be used to store gels for later. Another advantage of the gel casting stand is that I don’t have to tape the ends of the gel trays to make the gels. This is an advantage over many other systems which require taping the ends of their gel trays. To use the gels, remove the prepared gels in the gel trays from the casting stand. The gel tray containing the gel is then placed onto the gel bed in the gel box. The end of the gel which contains the wells is placed closest to the power supply. The gel box or tank can run one large or two small gels simultaneously. Buffer is poured into the gel box. This unit requires little buffer (about 200 ml). The box has a buffer level reference to ensure the proper amount of buffer is added. The cover is placed on the gel box. The gel box and lid form a mechanical, safety interlock, to which the power supply is attached. The small power supply, which comes with the unit, is inserted into the gel box.
The output from the power supply is 35 V, 50 V, 100 V, or 135 V. You can only run the gel at those voltages, a negative. The power supply connects directly to the gel box without the use of leads, a plus. When the power supply is in place, the gel box lid cannot be opened. A large display on the power supply shows the time. Controls on the power supply are on/off, voltage select (35, 50, 100, and 135 V), timer up and down and set. A flashing light in the time display indicates that current is being applied. Operation can be timed or not.
As a safety measure, the Gel XL Plus power supply employs a 0.8A resettable fuse which will blow if the buffer concentration is too high, leading to high resistance within the buffer and the gel. This higher resistance leads to higher temperature. Once it reaches 40ºC, the fuse will blow, adding an essential protection to the system.
There is little maintenance required, except for the usual cleaning of the trays and combs after use. We have not had any problems with this system.
Hee Chul Lee
Research Fellow
University of Michigan
Internal Medicine