Agent skill · Design & Presentation

bio-crispr-screens-in-vivo-screens

Designs and analyzes in vivo CRISPR screens in animal tumor models, organoids, and immune-cell adoptive transfers. Covers bottleneck math (250x cells/sgRNA requires ~25M cells implanted; impossible for most syngeneic models, forcing focused libraries), focused library design (Manguso 2017 Nature 547:413 immune screen; Chen 2015 tumor screens), CRISPR-StAR intrinsic-control screening (Uijttewaal 2025 Nat Biotechnol 43:1848), clonal-dynamics-limited detection, tumor-explant DNA recovery, syngeneic vs xenograft vs PDX considerations, and the relationship to downstream MAGeCK / drugZ analysis. Use

BioTender-maxgithub.com/BioTender-maxGitHub ↗
claude-codeships scriptsNOASSERTION
Install
npx skills add BioTender-max/awesome-bio-agent-skills --skill in-vivo-screens --agent claude-code

Same command for any agent — swap --agent for codex, cursor, copilot.

Facts
Files in the skill folder: 3
SKILL.md size: 13 KB
Bundled scripts: yes
Path: skills/bioskills/in-vivo-screens/SKILL.md
Open the folder on GitHub →
Where it comes from
Stars: 135
Language: Python

Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.

From the SKILL.md

## Version Compatibility Reference examples tested with: MAGeCK 0.5.9+, MAGeCK-VISPR 0.5.6+, pandas 2.2+, numpy 1.26+. Before using code patterns, verify installed versions match. If versions differ: - CLI: `mageck --version` - Reference focused libraries: Manguso 2017, Chen 2015, public Addgene aliquots If code throws ImportError, AttributeError, or TypeError, introspect the installed package and adapt the example to match the actual API rather than retrying. ## In Vivo CRISPR Screen Analysis **"Design or analyze an in vivo CRISPR screen"** -> Account for the dramatic bottleneck during animal implantation and tumor growth; use focused libraries; recover DNA from tumor explants; analyze with bottleneck-adjusted hit calling. - CLI: `mageck count` + `mageck test` for standard analysis - Special handling: bottleneck-adjusted coverage thresholds; per-tissue per-animal replicate structure ## The In Vivo Bottleneck Problem **Why in vivo screens differ from in vitro:** | Constraint | In vitro | In vivo | |------------|----------|---------| | Cells per condition | 10M-100M (unlimited) | Limited by injection volume (1-5M cells typical) | | Implant -> early tumor cell count | N/A | 10-100x d

What's inside
Steps it walks through
  1. Version Compatibility
  2. In Vivo CRISPR Screen Analysis
  3. The In Vivo Bottleneck Problem
  4. Focused Library Design for In Vivo
  5. CRISPR-StAR (Temporal Activation; Uijttewaal 2025)
  6. Syngeneic vs Xenograft vs PDX
  7. Tumor DNA Extraction and Sequencing
  8. Hit Calling for In Vivo
  9. Failure Modes
  10. Clonal dominance from low complexity
  11. Tumor DNA extraction yields no sgRNA reads
  12. In vivo PR-AUC against CEGv2 is poor
  13. Pre-screen Cas9 selection failure
  14. Inter-animal variability dominates hit calling
Ships with 2 files
  • examples/per_animal_meta_analysis.py
  • usage-guide.md
Commands it runs
Typical PCR + sequencing parameters for in vivo screens
Per-tumor DNA: 0.5-5 mg yield from typical syngeneic tumor
Per-sample sequencing depth: ≥500 reads/sgRNA at endpoint (lower than in vitro 300+)
Multiple animals per condition (n=5-10) to account for clonal variation
mageck count for in vivo
mageck count \
Option A: MAGeCK MLE with batch covariate
cat > in_vivo_design.txt <<EOF
mageck mle \
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About this skill
What does the bio-crispr-screens-in-vivo-screens skill do?

Designs and analyzes in vivo CRISPR screens in animal tumor models, organoids, and immune-cell adoptive transfers. Covers bottleneck math (250x cells/sgRNA requires ~25M cells implanted; impossible for most syngeneic models, forcing focused libraries), focused library design (Manguso 2017 Nature 547:413 immune screen; Chen 2015 tumor screens), CRISPR-StAR intrinsic-control screening (Uijttewaal 2025 Nat Biotechnol 43:1848), clonal-dynamics-limited detection, tumor-explant DNA recovery, syngeneic vs xenograft vs PDX considerations, and the relationship to downstream MAGeCK / drugZ analysis. Use

How do I install it?

Run `npx skills add BioTender-max/awesome-bio-agent-skills --skill in-vivo-screens --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.

Where does this skill come from?

From BioTender-max/awesome-bio-agent-skills, a repository with 135 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.

Is a popular skill a good skill?

Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.

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