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E-Gel from Invitrogen As laboratory personnel search for more streamlined protocols to maximize daily productivity, commercial vendors are designing a new family of convenience products. Premixed buffer stocks, minicolumns to isolate plasmid DNA, and even agar plates prepared using premeasured capsules have all allowed researchers to focus their efforts on experimental design rather than on laborious preparative tasks. To add to the growing list of such products is the new E-Gel™ from Invitrogen (Carlsbad, Calif.), the first bufferless, precast agarose gel system. Since its debut in March, E-Gel systems have been used by scientists to obtain quick and consistent DNA gel results. The E-Gel system consists of a 12-well minigel contained in a clear, UV-transparent cassette. Ethidium bromide is incorporated into the gel mixture for reproducible DNA staining results. Each sealed cassette houses the electrodes necessary for the gel run. The minigel is placed within the specially designed E-Gel Base which hooks up to any standard power supply. No buffer preparation is required, as the system uses a TAE-based dry buffer technology that is exclusive to Invitrogen. After a 2-minute prerun, the comb is removed and samples can be loaded. The gel run is complete in as little as 25 minutes. The cassette can then be transferred intact to a UV light box to examine the results. By keeping the gel in the cassette, the user can document both the gel percentage used and the position of each well, as this information is imprinted on the cassette in fluorescent characters. Several factors surrounded Invitrogen's decision to bring E-Gel into the marketplace. "Invitrogen is known for making routine laboratory procedures faster and more efficient," according to Mary Tulipani Cassoni, Invitrogen product manager. For labs that run gels every day, the steps of melting agarose and waiting for gels to solidify are time consuming. The inclusion of ethidium bromide within the gel matrix eliminates the time required for staining and destaining steps, as well as the handling and disposal of a hazardous material. The continuous flow of ethidium bromide using the dry buffer technology assures that the gels are not overstained. Invitrogen designed the E-Gel system with the lab consumer's needs in mind. For instance, a sturdy 1.2% gel (resolution 100 bp to 5 kb DNA) is offered for labs typically running standard 1% gels. The 4% agarose E-Gel™ was formulated for labs performing PCR assays and is meant to rival polyacrylamide for separation of a 20 bp ladder (resolution 20 bp to 500 bp DNA). A third product, the 2% E-Gel™, has a middle range resolution of 100 bp to 2 kb DNA. Because many labs that prepare their own gels on a daily basis routinely use a double comb system to examine 20, 30, or even 40 samples in a single gel, Invitrogen will investigate the possibility of incorporating this option into the E-Gel technology, according to Product Manager Cassoni. One innovation Invitrogen has just added to the product line is the E-Gel Opener, a small tool that allows the sealed cassette to be opened for gel purification of DNA fragments or transfer of DNA to a membrane for Southern analysis. Dr. Nancy Bowers, research associate at Portland State University, uses the 4% E-Gel system to examine the results of RFLP analyses of toxic cyanobacterial species. For her work, the use of a thinner gel allows smaller fragments to be detected because less DNA is required to obtain a signal. Bowers imagines future use of the E-Gel system in general biology teaching labs, where undergraduate students could be exposed to basic DNA techniques without having to pour gels or handle ethidium bromide. The quality and consistency of Bowers' E-Gel results led her to share her enthusiasm for the product with her colleague Dr. Debbie Duffield, a professor of biology at Portland State University. Duffield is now performing microsatellite analyses to study bottlenose dolphin population biology. Using the 4% E-Gels as an initial screen to check for the presence of PCR products, Duffield said that this type of visualization system allowed agarose gels to be run easily, quickly, and reliably. Duffield also cited Invitrogen's willingness to stand behind the product as another reason for her satisfaction with the new E-Gel system. For additional information on this product, contact Invitrogen at 800-955-6288 or visit the company web site at www.invitrogen.com. Author Linda Raab can be contacted at raabx004@maroon.tc.umn.edu

The 'E' means 'Easy': Invitrogen's E-Gel Precast Agarose Electrophoresis System

Oct 11, 1998

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