Over the past 10 years the MEGAscript™ Kit has earned the reputation of being the best high yield transcription kit available, and for good reason. As such, it is frequently used as a benchmark for comparison by other manufacturers who are continually trying to top the yields obtained with MEGAscript. However, yield is only half the story. A high quality transcription kit must make high yields of full-length RNA. When one compares the RNA produced by MEGAscript vs. the competition, the advantages of the MEGAscript Kit are obvious. Here we describe a set of rigorous tests comparing MEGAscript to another manufacturer's high yield transcription kit. We evaluated each kit for both yield and the capacity to synthesize full length transcripts of different lengths using three different analytical methods.
Comparing the Synthesized RNA
Similar RNA yields were produced by both kits as determined by simple mass quantitation based on TCA precipitation data (Figure 1). Examination of the RNA by bioanalyzer and gel analysis, however, reveals a very different story. Both kits were able to synthesize a 1 kb transcript, but only the MEGAscript Kit was able to produce full-length 4 kb and 9 kb transcripts. Figure 2 illustrates agarose gel analysis of the reaction products. Notice the virtual absence of full-length 4 kb and 9 kb product in the competitors' samples. Analysis on the Agilent 2100 bioanalyzer confirms and extends the gel data: full-length 4 kb and 9 kb product are barely detectable using the other kit. This startling failure prompted us to obtain a second kit of a different lot from the same manufacturer (Lots A52-90374 and A52-109100 were tested). We repeated the experiments and obtained identical results (data not shown).
While most transcription kits can synthesize a 1 kb RNA, reliable high quality synthesis of 4 kb and 9 kb RNA transcripts is a more stringent test of kit quality and reliability. Focused attention to the quality of every component and careful optimization of manufacturing processes combine to make the MEGAscript Kit a consistent and top performing product, deserving of its reputation. The next time you run across an ad for the 'best' high yield transcription kit, remember that yield is only part of the story.