Most any molecular biology lab that deals with DNA requires the use of agarose gels to isolate and purify DNA products. Especially necessary when making probes or genotyping animals, agarose gels are the standard and cheapest method for accomplishing DNA or RNA separation. The standard method is to melt the desired amount of agarose powder with the electrophoresis buffer (generally TAE or TBE) to obtain the desired percentage gel (typically 1-4% depending on the size of the product to be separated). The gel is usually poured in the cassettes provided with the electrophoresis buffer system.
To make this process much simpler and to save time, Bio-Rad sells ReadyAgarose™ Precast Gels. These are prepoured gels that come in different concentrations (0.8%, 1.0% and 3.0%). They are designed to fit the Bio-Rad Mini and Wide Subcell GT electrophoresis system. However, they also fit a variety of other models; I snap off the special tabs to use the gels with an Owl Spyder system. The gels come in mini size (7.1 cm) with 8, 12 or 2x8 wells and mini wide (15.6 cm) with 20, 32 and 2x32 wells. The gels come in a transparent tray with numbers on the top to help in locating the wells. They also come with or without ethidium bromide and in TBE or TAE buffer and have a shelf like of 6-12 months. The price ($9 per gel) is somewhat steep, however, although not nearly as much as the precast Invitrogen E-gels.
I have used these gels many times and find them to be pretty reliable. They are easy to use and save the time of measuring out agarose, melting and pouring the gels. They also eliminate the need to add and handle the ethidium bromide. The 32 and 2x32 gels can be used with multichannel pipettors, which also can save time. However, my one big complaint is that the 2x32 gels do require the addition of more ethidium as the ethidium diminishes towards the bottom of the gel and the bands can’t be visualized. Another drawback is the fact that you still have to use and deal with the buffer system and pay attention to the timing of the gel run. It also requires the same amount of running time as a standard agarose gel.
While it is nice and fast to not have to worry about pouring a gel, the system is not really that much more of a step-up from any standard agarose gel. If you are willing to pay the $9 per gel versus the ~$2 that a typical gel costs, they do save time. You are also limited to only 3 gel percentages; personally, I would like to see a 2% offered. If the gels already fit into your system, it might be worth buying them to save time, but I wouldn’t buy the Bio-Rad system for the purpose of using these gels. They offer nowhere near the convenience of the Invitrogen E-gel system, with its precast, bufferless gels which are self-contained, fast and timed so that you can’t forget about them. While the ReadyAgarose™ gels offer a few advantages, unless your time is so valuable that you can’t spend the extra 15 minutes that it takes to pour a typical agarose gel, they really don’t offer that many features that make it worth the extra expense.