bio-chipseq-differential-binding

bio-chipseq-differential-binding is a skill for Claude Code, Codex from PKU-YuanGroup/OpenAI4S. It costs 125 tokens per session (5,314 once invoked), scanned A, a copy of bio-chipseq-differential-binding, MIT.

A workflow for finding DNA regions where protein binding differs between experimental conditions using ChIP-seq data. ChIP-seq measures where proteins attach to DNA across the genome.

In plain words
What is it for?
Use it to compare binding between treatments, cell types, or other conditions and identify regions with statistically meaningful changes.
Why use it?
It accounts for sequencing depth and several kinds of measurement bias that can make simple comparisons misleading.

Skill for Claude CodeCodex

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

Good fit Use it to compare binding between treatments, cell types, or other conditions and identify regions with statistically meaningful changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding
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 PKU-YuanGroup/OpenAI4S --skill bio-chip-seq-differential-binding
Clone the repo
git clone --depth 1 https://github.com/PKU-YuanGroup/OpenAI4S

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 bio-chipseq-differential-binding

README.md
[![agentmods](https://agentmods.dev/badge/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding/github.svg)](https://agentmods.dev/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding)
Your own site
<a href="https://agentmods.dev/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding"><img src="https://agentmods.dev/badge/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding/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 bio-chipseq-differential-binding

Your own site · 80×15
<a href="https://agentmods.dev/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding"><img src="https://agentmods.dev/badge/skills/pku-yuangroup/openai4s/bio-chip-seq-differential-binding.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 125 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,314 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.
Origin 95% copy Near-identical to another mod 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 $0.00125 $0.05314
Opus 5 $0.00063 $0.02657
Sonnet 5 $0.00025 $0.01063
Haiku 4.5 $0.00013 $0.00531

Measured 7d ago against content hash 69b976a45992, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

bio-chipseq-differential-binding 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 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/pydeseq2_from_counts.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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

This is a copy

95% identical to bio-chipseq-differential-binding — 12 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/bioskills/bio-chip-seq-differential-binding/SKILL.md · 331 lines

How it starts

The opening of the file, as written. The whole thing — 331 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Version Compatibility

Reference examples tested with: DiffBind 3.20+, DESeq2 1.42+, edgeR 4.0+, csaw 1.36+, PyDESeq2 0.5+, NormR 1.28+, MAnorm2 1.2+, ChIPseqSpikeInFree 1.6+.

DiffBind 3.0+ changed defaults: summits=200 (was FALSE), dba.normalize() now required, blacklist filtering on by default, full library size normalization replaces reads-in-peaks. Always run packageVersion('DiffBind') and inspect dba.normalize(obj, bRetrieve=TRUE) to confirm what was applied.

Differential ChIP-seq Binding

"Compare protein-DNA binding between experimental conditions" -> Identify regions where IP signal changes significantly, accounting for sequencing depth, composition bias, trended biases, and global shifts that confound naive normalization.

  • R (BAM + peaks): DiffBind::dba() -> dba.count() -> dba.normalize() -> dba.analyze()
  • R (count matrix): DESeq2::DESeq() or edgeR::glmQLFTest() on a peaks-by-samples matrix
  • R (windows-based, global-shift-robust): csaw::windowCounts() -> csaw::normFactors() -> edgeR::glmQLFTest()
  • R (control-aware): normr::diffR(chip1.bam, chip2.bam, genome) joint binomial mixture
  • Python (count matrix): pydeseq2.DeseqDataSet()

Choice of normalization matters more than choice of test statistic (RLE vs TMM vs csaw bin-TMM on the same reference reads produce nearly identical results). Choose by which of the three normalization problems applies.

The Three Distinct Normalization Problems

Problem Symptom on MA plot Cause Fix
Composition bias Loess shifts off y=0 systematically Few high-signal peaks dominate read counts; small fold changes look large or inverted TMM on background 10 kb bins (csaw / DiffBind background=TRUE); NOT reads-in-peaks
Trended bias (intensity-dependent) Loess curve sweeps from + to - across abundance Library-prep efficiency varies with fragment abundance Non-linear loess offsets (csaw normOffsets); use cautiously — can over-normalize biology
Global shift (treatment changes most peaks) Loess entirely shifted off y=0; mean log2FC ≠ 0 Drug/perturbation changes the genome-wide level of binding (HDACi, BETi, EZH2i, target KD) Spike-in scaling (ChIP-Rx); no algorithmic fix works

Read the full file on GitHub · 331 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 7d ago First seen · 331 lines · 125 tokens per session scan A 69b976a45992

Subscribe to this mod's changes

bio-chipseq-differential-binding is a skill published in the GitHub repository PKU-YuanGroup/OpenAI4S (403 stars, last pushed today), licensed MIT. It adds 125 tokens to every session and 5,314 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to bio-chipseq-differential-binding, differing in 12 lines, and is treated as a copy.

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