Physics / mechanism
Cell-free systems (CFS) execute biological synthesis — proteins, nucleic acids, small molecules — outside living cells. The core machinery is a cell extract (typically E. coli, wheat germ, or CHO-derived) containing ribosomes, tRNA, polymerases, and co-factors, supplemented with an energy regeneration system (phosphocreatine, 3-PGA) and a DNA or mRNA template. Reaction volume spans nanolitres to litres. Protein yields have reached 2–4 mg/mL in optimised E. coli PURE-system batches; wheat-germ platforms hit ~1 mg/mL with eukaryotic folding fidelity. Synthesis cycles run 2–8 hours. Key parameters: ATP regeneration rate, template concentration, chaperone availability, and redox balance. Commercial platforms: Sutro Biopharma, Synvitrobio, Arbor Biosciences, New England Biolabs.
Competitive landscape
Cell-based expression (CHO, HEK293, yeast) dominates industrial protein manufacture — lower COGS at scale but 2–6 week development cycles and containment overhead. CFS trades unit economics for speed, programmability, and open-reaction access. Adjacent: ribosome display and mRNA display (selection, not production); solid-phase peptide synthesis (short peptides only, no folded domains); and microfluidic droplet encapsulation, which can host CFS reactions at femtolitre scale. The hardest competitive moat question is whether CFS yield economics close enough to justify platform switching for therapeutic proteins beyond early discovery.
Companies using
Connected ideas
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Frontier (open questions)
- To be added.