Cell-Free Expression

Protein Expression

A rapid method for gene expression analysis, PURExpress® is a novel cell-free transcription/translation system reconstituted from the purified components necessary for E. coli translation.

PURExpress® is a registered trademark of New England Biolabs, Inc.

Solutions for the Expression of Difficult Proteins

NEB has a long history in recombinant protein expression and has developed a wide array of solutions for proteins that are difficult to express.

NEB has a long history in recombinant protein expression and has developed a wide array of solutions for proteins that are difficult to express.

The PURExpress® System Kit Components

  • His-Tagged Translation Factors
    • Initiation Factors (IF1, IF2, IF3)
    • Elongation Factors (EF-Tu, EF-Ts, EF-G)
    • Release Factors (RF1, RF2, RF3)
    • Ribosome Recycling Factor
    • 20 Aminoacyl tRNA synthetases
    • Methionyl tRNA formyltransferase
  • E. coli Ribosomes
  • E. coli tRNAs
  • Energy Regeneration System
  • NTPs, Amino Acids, Salts, Buffer

In addition, recombinant T7 RNA polymerase is used to couple transcription to translation. The PURE system represents an important step towards a totally defined in vitro transcription/translation system, thus avoiding the “black box” nature of the cell extract-based systems.

Protein Expression Using the PURExpress® In Vitro Protein Synthesis Kit

25 µl reactions containing 250 ng template DNA were incubated at 37°C for 2 hours. 2.5 µl of each reaction was analyzed by SDS-PAGE using a 10–20% Tris-glycine gel. Note that proteins can be purified using reverse affinity chromatography (reagents not supplied). The red dot indicates the protein of interest. Marker M is the Protein Ladder (NEB #P7703)