Messenger RNA (mRNA) synthesis by in vitro transcription (IVT) is a cell-free process to produce RNA by enzymatic reactions. Synthesized RNA such as mRNA is widely utilized in research, drug development, vaccine production, and many other applications.

Key components of in vitro transcription are:

  • Linear DNA as a template
  • An RNA polymerase as a synthesizing enzyme, transcribing RNA from DNA
  • Nucleotides as building blocks, which may be modified or unmodified
  • Modifying enzymes for 5′ capping and 3′ poly-A tailing (for eukaryotic mRNA)

An RNase inhibitor and other components like pyrophosphatase may be added to the IVT reaction to help improve RNA yield.

T7 DNA polymerase synthesizing RNA

In vitro transcription with a T7 RNA polymerase.

mRNA capping and tailing

Capping and tailing of mRNA.

Scaling mRNA synthesis for different applications

The IVT reaction can be scaled to produce mRNA from micrograms to milligram, or even gram scale and beyond, for the amount needed for your intended application. For manufacturing or production of RNA at large scales for therapeutic development, quality standards and regulatory requirements of the raw materials must be considered.

Thermo Fisher Scientific offers a comprehensive portfolio of in vitro transcription products to meet the requirements for the entire spectrum of mRNA applications—from research to therapeutic development and vaccine production. Many of these products are available individually or as kits designed to facilitate in vitro transcription. 

Table 2. Recommended IVT solutions by mRNA synthesis scale.

ScaleMicro scaleMini scaleMid-scaleProduction scale
VolumeμLs to 200 mLUp to 500 mL1–5 L10–50 L
mRNA yields (from multiple runs per year)Microgram to milligram rangeMilligram rangeMilligram to gram rangeGram to kilogram range
  • Pre-clinical and toxicology studies
  • Process development
  • Process development
  • Clinical trials

Commercial manufacture

Performance needsHigh-throughputReproducibleScalableReliable
Product quality supportFor Research Use OnlyFor Research Use or Further ManufacturingFor Research Use or Further ManufacturingFor Research Use or Further Manufacturing
Recommend solutions

TheraPure GMP portfolio

* “TheraPure GMP” refers to the quality level of the raw, ancillary, or starting materials to be used for further manufacturing. TheraPure GMP products are manufactured in facilities with ISO 9001–certified quality management systems that operate in accordance with relevant good manufacturing practice (GMP) principles, as outlined in ICH Q7 or equivalent guidance documents or standards.

Intended use of the products mentioned on this page vary. For specific intended use statements please refer to the product label.