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GIBCO BRLTM Model S2001 Sequencing Gel Electrophresis Apparatus From Life Technologies When many of us started to sequence DNA, the technology was very primitive. The Klenow fragment of DNA polymerase-I was the only enzyme available, 7dG and dITP were almost unheard of, and the equipment was often mismatched and kludgy. In-house (or even, at times, in-lab) manufactured gel apparatuses led to a host of quirks and incompatibilities, many of which were propagated through numerous generations of the equipment in the name of "consistency." Having worked with-and often around-this type of sequencing apparatus for several years before I left the manual DNA sequencing field, I found it refreshing to see Life Technologies new S2001 DNA sequencing gel electrophoresis apparatus. The S2001 did not present any "Oh, wow!" surprises, but it is a soundly designed and well-thought-out manual system that includes some innovative ideas as well as several features we have come to expect in the more sophisticated automated instruments. The S2001 gel bed has been standardized to the 30 x 40 cm gel format that should be compatible with most commercial gel dryers, X-ray film, and autoradiography cassettes. A healthy variety of combs allows simple integration with most template preparation and sequencing reaction formats. The paired 14 cm, 48-sample sharkstooth combs can lead to easily readable three mm lanes; a single 96-well plate will yield 24 complete sequencing reactions, which can then be loaded on a single gel. A convenience many of us have grown used to with automated sequencing instruments is precision clamps to hold the gel plates onto the electrophoresis apparatus. Many manual systems use binder clips to hold the gel, while others (including the S2001's predecessor, Life Technologies S2 system) use a system of screw clamps. Incorrect pressure at this stage can also lead to a host of problems. In addition to gel artifacts caused through bending or squeezing the gel, too little clamping pressure allows the upper buffer reservoir to leak, whereas too much pressure, in addition to buffer leakage, can result in the plates breaking when clamp-induced stresses are subjected to Joule heating from the gel during electrophoresis. The S2001 has click-stopped clamps that are either open or closed, which helps ensure even, and correct, pressure against the gasket. It may at last be time to throw out the vacuum grease we have all used to help seal our electrophoresis systems. Emptying the buffer tanks after electrophoresis, often the least pleasant aspect of sequencing electrophoresis clean-up, has also been improved. Rather than emptying the buffer reservoirs with a syringe-or worse still, picking up the complete apparatus and trying to pour out the buffer-an automated-system-like drain path has been incorporated into the S2001. The upper buffer can be drained (using a tap that is obviously open or closed) into a separate lower buffer reservoir. Once the upper buffer reservoir is empty, the gel can be removed from the apparatus and processed. The separate reservoir keeps the lower (radioactive) and upper (uncontaminated) buffers separate, reducing the overall volume of contaminated liquid waste. The S2001 appears to be a solid system. It is well designed, flexible, and compatible with most other gel-processing apparatus. Life Technologies also manufactures an optional cooling base that the company claims will reduce electrophoresis times by up to one-third by allowing higher electrophoresis voltages. For those who work in sequencing groups where throughput or cost considerations do not allow for the transition to automated systems, and for researchers who perform radiolabeled DNA analysis for techniques that have not yet routinely succumbed to fluorescent techniques, the S2001 will be a valuable system. For more information, visit Life Technologies web page www.lifetech.com or (800) 828-6686. Bob Sinclair is a freelance writer based in Salt Lake City, Utah. He can be reached at bobsinclair@tech-write-edit.com

S2001 Sequencing Apparatus From Life Technologies

The Scientist Staff

Mar 1, 1998

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