The CleanCap and ARCA approaches each have their own set of pros and cons. The advantages of each approach vary depending on the specific needs of the scientists.

CleanCap is the latest generation of cap analogs and enables synthesis of cap-1 mRNA in a single step, but can be costly and often has patent/licensing requirements. ARCA synthesizes cap-0 mRNA first during the IVT reaction. An additional reaction, performed by an enzyme such as mRNA cap 2'-O-methyltransferase, is required to produce cap-1 mRNAs. The capping efficiency of ARCA is slightly low (50–80%) compared to CleanCap (>95%). Regardless, the lack of licensing requirements for ARCA attracts some users.

The linearized template vector in Cloning Kit for mRNA Template or Takara IVTpro mRNA Synthesis System has AGG as the transcription start site (Figure 1). This makes the vector compatible with use of CleanCap Reagent AG (No. N-7113 or N-7413).

For the vector information and a detailed protocol of in vitro transcription along with CleanCap reagents, please see the Takara IVTpro product overview or the User Manuals for Takara IVTpro mRNA Synthesis System or Takara IVTpro T7 mRNA Synthesis Kit. 

If you use ARCA for co-transcriptionally capping the mRNA using Takara IVTpro mRNA Synthesis System, it is necessary to modify the transcription start site. In this case, the Linearized Template Vector’s start site (+1 position) must be changed from A to G (Figure 2).

To learn more, explore our comprehensive selection of in-vitro transcription products.