Compression Woes Begone

Companies produce DNA sequencing kits with the expectation that their kits will outperform their competitors' kits. While the majority of available kits boast better performance and superior results and have pictures to prove it, it is not always possible to reproduce the promised results of some kits. It has been my experience that you can't tell how good a kit is until you try the protocol yourself and see if the outcome is as advertised. Most importantly, though, does the kit you selected perform the DNA sequencing that you set out to do? I have found one kit that not only meets all of its advertised expectations but can be modified to suit my own special nonstandard sequencing needs as well. Comparison of DNA sequencing reactions conducted with standard kit (left) showing a comparison in the boxed region, and with SequiTherm EXCELTM II from Epicentre (right), showing resolution of the compression. SequiTherm EXCEL II by Epicentre Technologies is a non-Taq-based thermostable DNA sequencing kit that is so flexible with its protocol that it can be adapted to do any kind of sequencing imaginable. Having used SequiTherm EXCEL II kit to sequence DNA from as few as 50 bases long up to 500 bases in length without any problems, I know of no other sequencing method that resolves GC compressions better than SequiTherm EXCEL II. I have found in sequencing some difficult templates that the GC compression resolving power of SequiTherm EXCEL II surpasses even the most commonly used kits. Best of all, the kit is user flexible. 35S, 32P, or 33P can all be used easily. Company literature claims that the timing of the template denaturation, primer annealing, and primer extension steps is not critical and allows for simultaneous manipulations of many samples by hand. At one point I denatured a template with a series of primers, left the reaction on my bench for 25 minutes, continued the reactions with terminations and stopping, ran the samples out on a gel, and was surprised to find the reactions were perfect. Try that with any other kit! Now I pause reactions occasionally when I need to and do not worry about the success of sequencing with Sequitherm EXCEL II. The folks at Epicentre Technologies know that they have a great DNA sequencing kit. It is substantially improved over the previous-generation SequiTherm EXCEL II Kit and has adaptability that no other kit can offer in a single enzyme chemistry. SequiTherm EXCEL II is very affordable, being much less expensive than some competitor kits, and does a better job of sequencing DNA than other kits I have tried. Aspects of SequiTherm EXCEL II that stand out include an adaptable protocol that allows for multi-isotope usage and cycle sequencing or isothermal (noncycle) sequencing. In addition, the extensive troubleshooting guide included with each kit actually makes sense and suggests alternative solutions and protocols, rather than merely offering a problem identification list. The protocol is written clearly and in a way that allows the end user to alter the protocol to meet his or her DNA sequencing requirements. Finally, a fine product along with intelligent customer service and patient technical support by the staff at Epicentre Technologies makes SequiTherm EXCEL II the choice DNA sequencing method for radioisotope sequencing when GC compressions are a problem, and no other method has resolved them. For more information contact Epicentre at 800-284-8474 or visit the company website at www.epicentre.com. Glenn Dawes is a Research Assistant at Affymax Research Institute and can be reached at glenn_dawes@amgates.affymax.com

Compression Woes Begone

The Scientist Staff

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Comparison of DNA sequencing reactions conducted with standard kit (left) showing a comparison in the boxed region, and with SequiTherm EXCEL^TM II from Epicentre (right), showing resolution of...