The MEGAscript® Kit is the most frequently cited large-scale transcription kit, and with good reason. It enables the consistent transcription of high yields of full-length RNA (Figure 1). Ambion offers a complete line of products specifically optimized to generate the following products:

  • capped RNA
  • dsRNA transcripts
  • uncapped RNA
  • amplified RNA
  • short RNA transcripts
  • milligram quantities of transcript

MEGAscript: Consistent, High Yields of RNA Transcripts

Using the MEGAscript Kit, you can produce over 120 µg of RNA from 1 µg of DNA template. This is 10-50 times the amount of RNA produced by conventional transcription (Figure 2). Reactions are versatile and can be manipulated to include specialized reagents such as modified nucleotides or additional polymerase. In addition, Ambion has optimized the transcription of short (20-500 nt) DNA templates with the MEGAshortscript™ Kit. This patented technology was designed to maximize the yield of short RNA transcripts from plasmid, oligonucleotides, and PCR product templates.


Figure 1. Electropherogram of RNA Transcripts of Different Sizes. In vitro transcription was performed using 1, 4, or 9 kb templates with Ambion's MEGAscript® Kit according to protocol. 20 µl reactions were diluted to 100 µl and 1 µl was assessed on the Agilent 2100 bioanalyzer. The single primary peak is indicative of product quality while the area under the peak is related to yield.


Figure 2. MEGAscript® vs. Conventional In Vitro Transcription Reactions. 20 µl transcription reactions containing 1 µg template, T7 MEGAscript components and [32P]UTP, were incubated at 37°C. 1 µl aliquots were removed at 1 hr intervals and acid precipitable cpm determined by scintillation counting.

mMESSAGE mMACHINE®: Translatable Capped RNA

For high yields of capped RNA, MEGAscript technology is incorporated into the mMESSAGE mMACHINE® Kit. This kit contains an optimized ratio of cap analog to GTP, for the best trade off between yield and proportion of capped transcripts (80% capped). Furthermore, you can obtain 100% translatable capped RNA with the mMESSAGE mMACHINE T7 ULTRA Kit. This kit uses a unique cap analog that only incorporates in the functional, translatable orientation, resulting in the synthesis of capped RNAs that are 100% translatable. 

MEGAscript® RNAi: dsRNA Synthesis for RNAi

In one complete kit, you can generate ready-to-use double-stranded RNA (dsRNA) for RNAi experiments in non-mammalian systems. Unlike competing products, the MEGAscript RNAi Kit provides reagents to eliminate DNA template, single stranded RNA, and free nucleotides. The MEGAscript RNAi Kit allows researchers to synthesize 50 to 80 µg or more of dsRNA, up to 1.2 kb in length, in a single transcription reaction. 

MessageAmp™ II: RNA Amplification

Amplify RNA with MEGAscript technology using the MessageAmp™ II aRNA Amplification Kit. The MessageAmp II Kit can amplify as little as 100 ng of input RNA in a single round for GeneChip® analysis. A rationally engineered M-MLV RT, ArrayScript™, is provided in the kit to maximize yields of full-length cDNA. cRNA synthesis is powered by MEGAscript technology. These features result in high labeling efficiency, yielding consistently high percentages of Present Calls, and low 3'/5' ratios in GeneChip analysis. This procedure is compatible with biotin, cyanine dye (Perkin Elmer), and Cy™Dye (Amersham Biosciences) labeling either during or after aRNA amplification. For additional information, see RNA Amplification Just Got Better.

Bulk Transcription - Milligram Quantities of RNA

If you have a project or application that requires large amounts of RNA transcripts, Ambion can meet your needs with its bulk and custom products. Our MEGAscript technology has been optimized to produce milligram quantities of RNA.