cell-free-expression

cell-free-expression is a skill for Claude Code, Codex from adaptyvbio/protein-design-skills. It costs 67 tokens per session (3,184 once invoked), scanned A, original, MIT.

Guidance for making proteins without living cells, using extracts or purified biological components in a reaction tube. Cell-free protein synthesis can be used to test protein production without growing cells.

In plain words
What is it for?
Choosing a cell-free system, improving DNA templates, troubleshooting expression and aggregation, and planning production experiments for different protein types.
Why use it?
It helps identify why a protein is not produced, is made in low amounts, or clumps together. It also helps choose a reaction system suited to difficult proteins, such as toxic, membrane, or disulfide-rich proteins.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Choosing a cell-free system, improving DNA templates, troubleshooting expression and aggregation, and planning production experiments for different protein types.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/adaptyvbio/protein-design-skills/cell-free-expression
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add adaptyvbio/protein-design-skills --skill cell-free-expression
Clone the repo
git clone --depth 1 https://github.com/adaptyvbio/protein-design-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cell-free-expression

README.md
[![agentmods](https://agentmods.dev/badge/skills/adaptyvbio/protein-design-skills/cell-free-expression/github.svg)](https://agentmods.dev/skills/adaptyvbio/protein-design-skills/cell-free-expression)
Your own site
<a href="https://agentmods.dev/skills/adaptyvbio/protein-design-skills/cell-free-expression"><img src="https://agentmods.dev/badge/skills/adaptyvbio/protein-design-skills/cell-free-expression/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for cell-free-expression

Your own site · 80×15
<a href="https://agentmods.dev/skills/adaptyvbio/protein-design-skills/cell-free-expression"><img src="https://agentmods.dev/badge/skills/adaptyvbio/protein-design-skills/cell-free-expression.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,184 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium analysis-evasion · line 1
    Suspicious Unicode normalization or mixed-script content
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00067 $0.03184
Opus 5 $0.00034 $0.01592
Sonnet 5 $0.00013 $0.00637
Haiku 4.5 $0.00007 $0.00318

Measured 11d ago against content hash f6ec951e3962, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

cell-free-expression scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/cell-free-expression/SKILL.md · 292 lines

How it starts

The opening of the file, as written. The whole thing — 292 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cell-Free Protein Synthesis (CFPS)

System Selection Guide

System Best For Yield PTMs Disulfides Cost
E. coli extract Rapid prototyping, prokaryotic proteins High (100-400 μg/mL) None Poor (reducing) Low
E. coli PURE Defined conditions, unnatural AAs Medium (50-150 μg/mL) None Controllable High
Wheat germ Eukaryotic proteins, membrane proteins High (100-500 μg/mL) Limited Moderate Medium
Rabbit reticulocyte Mammalian proteins, post-translational studies Low (10-50 μg/mL) Some Poor High
Insect (Sf21) Glycoproteins, complex folds Medium (50-100 μg/mL) Glycosylation Good High
HeLa/CHO Native mammalian proteins Low (10-50 μg/mL) Full mammalian Good Very High

CFPS Troubleshooting Matrix

Problem Likely Causes Design Fix Reagent Fix
No expression Rare codons at N-terminus, poor RBS Codon optimize first 30 codons Use BL21-CodonPlus extract
Low yield Strong mRNA secondary structure, template issues Optimize 5' UTR (ΔG > -5 kcal/mol) Increase Mg²⁺ (10-18 mM), ATP
Aggregation Hydrophobic protein, fast translation Add solubility tags (MBP, SUMO) Add 0.1% Tween-20, chaperones
Inactive protein Misfolding, missing cofactors Slow translation (use rare codons!) Add GroEL/ES, DnaK/J
Truncation Rare codon clusters, mRNA instability Remove AGG/AGA/CUA clusters Supplement rare tRNAs
Degradation Proteolysis N-terminal Met-Ala Add protease inhibitors

Codon Optimization for CFPS

Codons to Avoid in E. coli CFPS

Codon Amino Acid Issue tRNA Abundance
AGG Arg Very rare, stalling 0.2%
AGA Arg Very rare, stalling 0.4%
CUA Leu Low abundance 0.4%
AUA Ile Rare 0.5%
CGA Arg Inefficient decoding 0.6%
CCC Pro Can cause pausing 0.5%
GGA Gly Moderate 1.1%

Read the full file on GitHub · 292 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 292 lines · 67 tokens per session scan A f6ec951e3962

Subscribe to this mod's changes

cell-free-expression is a skill published in the GitHub repository adaptyvbio/protein-design-skills (158 stars, last pushed 3mo ago), licensed MIT. It adds 67 tokens to every session and 3,184 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

cell-free-protein-expression

Cell-free protein synthesis (CFPS) planning and optimization guidance. Use when: (1) Planning CFPS experiments, (2) Troubleshooting low yield or aggregation, (3) Optimizing DNA template design for CFPS, (4) Expressing difficult proteins (disulfide-rich, toxic, membrane).

BioTender-max/awesome-bio-agent-skills · 69 tokens

cell-free-expression

Guidance for cell-free protein synthesis (CFPS) optimization. Use when: (1) Planning CFPS experiments, (2) Troubleshooting low yield or aggregation, (3) Optimizing DNA template design for CFPS, (4) Expressing difficult proteins (disulfide-rich, toxic, membrane).

BioTender-max/awesome-bio-agent-skills · 67 tokens

cell-free-expression

Guidance for cell-free protein synthesis (CFPS) optimization. Use when: (1) Planning CFPS experiments, (2) Troubleshooting low yield or aggregation, (3) Optimizing DNA template design for CFPS, (4) Expressing difficult proteins (disulfide-rich, toxic, membrane).

BioTender-max/ProteinClaw · 67 tokens

cell-free-protein-expression

Cell-free protein synthesis (CFPS) planning and optimization guidance. Use when: (1) Planning CFPS experiments, (2) Troubleshooting low yield or aggregation, (3) Optimizing DNA template design for CFPS, (4) Expressing difficult proteins (disulfide-rich, toxic, membrane).

zongtingwei/Bioclaw_Skills_Hub · 69 tokens

binding-characterization

Guidance for SPR and BLI binding characterization experiments. Use when: (1) Planning binding kinetics experiments, (2) Troubleshooting poor/no binding signal, (3) Interpreting kinetic data artifacts, (4) Choosing between SPR vs BLI platforms.

FreedomIntelligence/OpenClaw-Medical-Skills · 57 tokens

binding-characterization

Guidance for SPR and BLI binding characterization experiments. Use when: (1) Planning binding kinetics experiments, (2) Troubleshooting poor/no binding signal, (3) Interpreting kinetic data artifacts, (4) Choosing between SPR vs BLI platforms.

BioTender-max/awesome-bio-agent-skills · 57 tokens