Every once in a while a product comes along that substantially improves a commonly-used laboratory technique. One such innovation is the FlashGel System from Lonza and the technique that has gotten a shot in the electrode is agarose gel electrophoresis.
Given the extent of the ad campaign that was mounted for this product, most researchers have probably at least seen a picture of the gadget. However, far fewer may have actually had the opportunity to use one. Since my work recently has required daily, or twice daily, pouring of agarose gels, I was immediately attracted to the ads and ultimately purchased one. More correctly, I purchased 2 boxes of gels and received the FlashGel device gratis. I have since gone through a box a gels and can confirm that it does pretty much what the ads say it can do. Namely, run a DNA gel from start to finish in less than 5 min and with excellent resolution.
The FlashGel System consists of a small (approx. 10 x 13 x 5 cm) platform that serves as both the power supply and transilluminator. Preparing the system for running a gel consists simply of tearing open a pouch containing a gel, removing 2 pieces of tape, and plugging the gel into the device. These steps can literally be completed in 10 seconds. Prior to loading samples, each of the 13 wells must first be filled with 7 ul water. Up to 5 ul sample can then be added to the wells and the gel is run at 275 V. With the transilluminator on, you can see the DNA migrating through the gel. Five min is usually more than enough time for sufficient migration. The gel cartridge can then be removed and photographed using a UV transilluminator or a Dark Reader (Clare Chemical Research, Inc., Dolores, CO).
The good points include the obvious, i.e. convenience and speed. Let’s say you have 15 min before you have to leave for the day but your PCR just finished and you’re anxious to see the results. With conventional agarose gel electrophoresis, you wouldn’t even consider running a gel. With a FlashGel you can. An additional benefit is the sensitivity of the system. Lonza claims that the optimal amount of DNA per band is 5 – 20 ng. This means you can load about 1/5 the amount you would normally load on a conventional gel. This can be very important with precious samples.
The less-than-desirable points also include the obvious, i.e. there’s a lot of plastic to throw away with every gel you run. Each FlashGel comes complete with gel, buffer chambers, and electrodes. The whole thing is tossed out after the run. With this in mind, it might be a good idea to use these devices for special occasions, like when you really need the results fast, or you have very little sample to spare. Another possibility is to reload the gel after a run so you get 2 runs per gel instead of one. I tried this once and noticed a little spreading of the bands but the gel was still readable. Some other marginally negative points: 1) FlashGels are only for analytical purposes (i.e. no gel extraction possible). 2) So far they only come in one agarose percentage. The Lonza DNA ladder goes from 100 bp to 4 kb and the resolution within this range is very good. Outside of this range, the resolution is less than optimal. 3) The gels have 13 lanes. If you only have a couple of samples, it’s probably not worth it to burn through a FlashGel. Instead, use the system for instances when you have close to a full gel’s worth.
Overall, the FlashGel System is an incredibly fast, effortless, and sensitive method for carrying out DNA electrophoresis. At about $10 per gel, it’s much more expensive than pouring your own and generates more waste for the landfill. However, the expense and waste can be justified for certain circumstances. The one danger is that these gels can be addictive. The speed and convenience is very easy to get used to.
Michael Campa, Ph.D.
Assoc. Research Professor of Radiology
Duke University Medical Center