Alphagenome Single Variant Analysis
google-deepmind/science-skills
Analyzes genetic variant effects on gene expression (RNA-seq), chromatin accessibility (DNASE), histone marks (ChIP), and transcription factors using the AlphaGenome API.
Detect single-nucleotide crosslink (CL) sites in CLIP-seq data using truncation patterns (iCLIP/eCLIP CITS), crosslink-induced mutations (HITS-CLIP CIMS deletions, PAR-CLIP T-to-C), or…
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detection --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/clip-seq/crosslink-site-detection .claude/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .claude/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detectionType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detection --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/clip-seq/crosslink-site-detection .agents/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .agents/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detection --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/clip-seq/crosslink-site-detection .cursor/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .cursor/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/GPTomics/bioSkills.git --path clip-seq/crosslink-site-detection--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detection --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/clip-seq/crosslink-site-detection .gemini/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .gemini/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detectionInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .github/skills && cp -r skills-src/clip-seq/crosslink-site-detection .github/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .github/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install GPTomics/bioSkills bio-clip-seq-crosslink-site-detection --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/GPTomics/bioSkills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/clip-seq/crosslink-site-detection .opencode/skills/bio-clip-seq-crosslink-site-detection && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "bio-clip-seq-crosslink-site-detection" agent skill from https://github.com/GPTomics/bioSkills/tree/main/clip-seq/crosslink-site-detection into .opencode/skills/bio-clip-seq-crosslink-site-detection/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bio-clip-seq-crosslink-site-detection", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
bio-clip-seq-crosslink-site-detectionDetect single-nucleotide crosslink (CL) sites in CLIP-seq data using truncation patterns (iCLIP/eCLIP CITS), crosslink-induced mutations (HITS-CLIP CIMS deletions, PAR-CLIP T-to-C), or…
Bio Clip Seq Crosslink Site Detection is an agent skill from GPTomics/bioSkills. Detect single-nucleotide crosslink (CL) sites in CLIP-seq data using truncation patterns (iCLIP/eCLIP CITS), crosslink-induced mutations (HITS-CLIP CIMS deletions, PAR-CLIP T-to-C), or HMM/kernel-density methods (PureCLIP, PARalyzer, CTK). Use when single-nucleotide resolution is required for motif registration (mCross), allele-specific binding (BEAPR), variant-effect prediction, or comparing crosslink chemistry across CLIP variants.
Its SKILL.md is about 5k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files (for example `examples/detect_crosslinks.sh` and `usage-guide.md`).
It sits in Research & Science, covering Bioinformatics. The repository describes itself as: a set of SKILLS.md for doing bioinformatics with agents like claude code. The licence is MIT.
Read from SKILL.md and the folder at commit d91ed3d. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Ships script files (Shell), which the agent can run.
Shell commands in SKILL.md call:
pipFrom the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md. Its commands use pip, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Bio Clip Seq Crosslink Site Detection loads about 5k tokens when it runs. Until then it costs about 119 tokens; SKILL.md has 2,444 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
The full file from GPTomics/bioSkills at commit d91ed3d, republished under its MIT licence (© GPTomics). 2,444 words, ~4,982 tokens.
.claude/skills/bio-clip-seq-crosslink-site-detection/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.Reference examples tested with: PureCLIP 1.3.1+, CTK 1.1.4+, PARalyzer 1.5+, wavClusteR 2.34+, pyCRAC 1.5+, samtools 1.19+, bedtools 2.31+, pysam 0.22+, R 4.3+.
Before using code patterns, verify installed versions match. If versions differ:
<tool> --version then <tool> --help to confirm flagspip show <package> then help(module.function) to check signaturespackageVersion('<pkg>') then ?function_name to verify parametersIf code throws unexpected errors, introspect the installed tool and adapt the example to match the actual CLI rather than retrying.
"Detect single-nucleotide crosslink sites in my CLIP data" -> Identify the exact base where the protein-RNA UV adduct caused the reverse transcriptase to stop (truncation, in iCLIP/eCLIP), to read through with a mutation (deletion in HITS-CLIP, T->C in PAR-CLIP), or to leave a multi-base signature (PARalyzer kernel density for PAR-CLIP). Single-nucleotide resolution is the foundation of motif registration (mCross), allele-specific binding (BEAPR/ASPRIN), variant-effect prediction, and the most rigorous comparisons across CLIP variants. The detection chemistry differs by CLIP type: iCLIP/eCLIP read 5' end is one nucleotide downstream of the crosslink (CITS); PAR-CLIP reads contain T->C transitions at the crosslink (CIMS substitution); HITS-CLIP reads contain deletions at the crosslink (CIMS deletion).
pureclip -i dedup.bam -bai dedup.bam.bai -g genome.fa -ibam sminput.bam -ibai sminput.bam.bai -o crosslinks.bed -or regions.bed -nt 8 -dm 8parseAlignment.pl --map-qual 1 --min-len 18 --mutation-file mut.txt dedup.bam dedup.bed then tag2cluster.pl ... -cs5 5 -m 1 for truncation-clustergetMutationType.pl dedup.bed mut.txt -type del then CIMS.pl dedup.bed mut.txt -big -c -p 0.01 cims.bedgetMutationType.pl dedup.bed mut.txt -type sub -nuc t -mut c then CIMS.pl dedup.bed t2c.mut -p 0.001 t2c_cims.bedPARalyzer params.ini (parameters file defines read length, min reads per cluster, mutation rate threshold)wavClusteR::filterClusters(cl, snps=NULL, filterFC=FALSE) after wavelet clusteringSingle-nt CL sites are the input to mCross motif registration (see clip-seq/clip-motif-analysis), to BEAPR/ASPRIN allele-specific binding analyses, and to RBPNet/DeepRiPe deep-learning models (see clip-seq/clip-deep-learning). They are NOT a replacement for broad peak calls; the two outputs are complementary. A common downstream error is passing a CLIPper peak BED to mCross instead of a PureCLIP single-nt BED - mCross requires the single-nt resolution to register motif position relative to the crosslink offset.
The detection method must match the underlying chemistry of how the reverse transcriptase encountered the protein-RNA adduct:
| CLIP variant | RT behavior at CL | Detection signature | Sensitivity (CL captured per read) | Sequence bias |
|---|---|---|---|---|
| iCLIP / iCLIP2 / iCLIP3 / eCLIP / irCLIP / FLASH | Truncates at adduct | 5' end of cDNA = CL site - 1 | ~80% of reads truncate; the minority read through | Strong U bias at CL sites |
| HITS-CLIP | Reads through with deletion (~8-20% of tags) | Single-base deletion in read | ~8-20% of tags contain a deletion at the CL site | U bias plus sequence-specific deletion rate |
| PAR-CLIP (4SU) | Reads through with T->C (20-50% of T positions in crosslinked reads) | T->C transition (or G->A on reverse strand) | Per-T rate 20-50%; per-read 1-5 conversions | Restricted to T positions; depends on 4SU incorporation rate |
| PAR-CLIP (6SG) | Reads through with G->A | G->A transition | Lower rate than 4SU T->C | Restricted to G positions |
| miCLIP / miCLIP2 (m6A) | Primarily truncation at the m6A site (RT stops at antibody-trapped m6A); secondary C->T transition observed in a subset of reads at m6A | 5' end (CL -1); C->T rate is a feature used by m6Aboost ML in addition to truncation, not a stand-alone primary signal | Mixed; m6Aboost ML integrates truncation + sequence context to score | DRACH motif context required |
| STAMP | C->T editing on target (not crosslink) | C->T editing in mRNA reads | NA (editing-based; not crosslink-based) | N/A |
| TRIBE | A->I editing on target | A->G in cDNA (I read as G) | NA | Adjacent to ADAR consensus |
| Tool | CLIP variant | Detection signal | Statistical model | Output resolution | Strength | Fails when |
|---|---|---|---|---|---|---|
| PureCLIP (Krakau 2017) | iCLIP/eCLIP/PAR-CLIP | Truncation + enrichment + CL motif | Non-homogeneous HMM | Single-nucleotide | The most comprehensive HMM model | Lowest F1 among callers benchmarked in Boyle 2023 on broad-binding RBPs (highly focal) |
| CTK CITS (Shah 2017) | iCLIP/eCLIP | Truncation only | Empirical FDR vs background | Single-nucleotide | Simple, well-validated for iCLIP | Less granular than PureCLIP; no HMM smoothing |
| CTK CIMS deletion (Shah 2017) | HITS-CLIP | Single-base deletions | Empirical FDR | Single-nucleotide | Standard for HITS-CLIP | Requires deletion-tolerant aligner (BWA -e) |
| CTK CIMS T->C (Shah 2017) | PAR-CLIP | T->C substitutions | Empirical FDR | Single-nucleotide | Alternative to PARalyzer | Less popular than PARalyzer |
| PARalyzer (Corcoran 2011) | PAR-CLIP | T->C transitions, kernel density | Kernel density estimation | Cluster (10-50 nt) | Field standard for PAR-CLIP | Cluster-level, not single-nt; needs careful parameter tuning |
| wavClusteR (Comoglio 2015) | PAR-CLIP | T->C with wavelet smoothing | Wavelet transform + clustering | Cluster | Robust to sequencing depth variability | Less single-nt; legacy R package |
| pyCRAC / kPLogo | CRAC (yeast) | Read truncation + deletion | Empirical | Single-nucleotide | Original CLIP analytics tool | Yeast-focused; perl/python legacy |
| Piranha bins | Any | Coverage in bins | ZTNB | Bin-level (50-200 nt) | Not crosslink-specific | Bin width too coarse for single-nt |
| HOMER tag2pos | Any | 5' end position | None | Read-end positions only | Quick truncation site dump | No statistical filtering |
| omniCLIP | Any | Coverage + variant pattern | Dirichlet-multinomial HMM | Region | Not focal | Too broad for single-nt |
| iCount (paths) | iCLIP | Crosslink site cluster | Empirical | Cluster | Used in nf-core/clipseq | Less single-nt than PureCLIP |
Methodology evolves; PureCLIP 2.0 and CTK 1.2 have minor flag changes; PARalyzer parameters need careful tuning per-RBP. Cross-validate single-nt sites with at least two tools when high-confidence reporting is required.
Three orthogonal approaches:
Truncation-based (CITS, PureCLIP) -- Find positions enriched in cDNA 5' ends. The RT enzyme stops at the adduct; the 5' end of the read maps to CL site - 1. Used for iCLIP/eCLIP. Pro: high yield (~80% of reads truncate). Con: U bias of crosslinking inflates U positions.
Mutation-based (CIMS for deletions/substitutions; PARalyzer for T->C) -- Find positions with crosslink-induced mutations. RT reads through the adduct with high mutation rate at the CL position. Used for HITS-CLIP (deletions, ~8-20%) and PAR-CLIP (T->C, 20-50%). Pro: less U bias; PAR-CLIP signal is restricted to T positions. Con: lower yield (only mutated reads count).
HMM-based (PureCLIP, omniCLIP) -- Joint model of enrichment + CL signature + sequence context. State the most-likely posterior probability of CL state per nucleotide. Used across CLIP variants. Pro: integrates multiple signals; explicit input normalization. Con: F1 ~0.2 on bulk RBPs (very focal); single-nt resolution at the cost of breadth.
| Goal | Method | Tool |
|---|---|---|
| Single-nt CL map for motif registration (mCross) | HMM | PureCLIP |
| Truncation-based ENCODE-compatible iCLIP | Truncation | CTK CITS |
| PAR-CLIP T->C signal | Mutation | PARalyzer (cluster) or CTK CIMS sub T->C (single-nt) |
| HITS-CLIP deletion signal | Mutation | CTK CIMS deletion |
| Cross-CLIP-variant comparable single-nt | HMM | PureCLIP (all variants) |
| Allele-specific CLIP (BEAPR) | Truncation + ASB | PureCLIP CL sites + WASP-filtered BAM |
| Variant effect (computational from CL) | HMM | PureCLIP + downstream DeepRiPe (see clip-deep-learning) |
| Yeast / CRAC | Truncation + deletion | pyCRAC |
Trigger: RBP with low IP enrichment; SMInput depth uneven; PureCLIP run on full genome without -iv interval.
Mechanism: PureCLIP HMM convergence is sensitive to coverage depth. On regions with < 5 reads/100 bp the HMM defaults to background state; if half the genome is sparse, the state distributions become bimodal and the entire run takes > 24 h or runs out of memory.
Symptom: PureCLIP "Convergence not reached" warning; or output has 0 CL sites; or runtime > 24 h on standard server.
Fix: Restrict analysis to expressed transcripts: -iv expressed_tx.bed. Or filter the BAM to high-coverage regions first. Test on chr22 first to verify parameters before genome-wide run.
Trigger: RBP with broad binding (PUM2 3' UTRs, SR proteins exonic enhancers); using PureCLIP exclusively.
Mechanism: PureCLIP HMM emits the CL state at very high stringency. The Boyle 2023 Skipper benchmark reports PureCLIP as the most focal caller with low recall on broad-binding RBPs.
Symptom: PureCLIP CL site count is 100x lower than CLIPper / Skipper peak count.
Fix: Use PureCLIP for single-nt CL maps AND CLIPper/Skipper for broad-zone peak calls. They are complementary, not substitutes. PureCLIP -or regions output is broader than -o sites but still focal.
Trigger: CTK CITS run on PAR-CLIP data.
Mechanism: PAR-CLIP RT reads through the adduct (T->C mutation), not truncates. The 5' end of PAR-CLIP reads is at the fragment 5' end, not the CL site.
Symptom: CITS returns few sites; the sites that ARE returned do not align with the T->C mutation positions.
Fix: For PAR-CLIP use PARalyzer or CTK CIMS substitution mode (-type sub -nuc t -mut c). CITS is iCLIP/eCLIP only.
Trigger: CTK CIMS run with -type del on iCLIP data.
Mechanism: iCLIP RT truncates, doesn't delete. The deletion rate is < 1% in iCLIP (background level), so CIMS finds nothing significant.
Symptom: CIMS output BED has < 100 sites genome-wide.
Fix: Use CTK CITS for iCLIP (truncation-based) or PureCLIP. CIMS deletion is HITS-CLIP / older PAR-CLIP only.
Trigger: PARalyzer default parameters on a new RBP; cluster count unexpected.
Mechanism: PARalyzer's kernel-density approach has 5+ parameters: minimum read depth, minimum mutation read count, mutation rate threshold, bandwidth, kernel type. Different combinations produce 5-100x different cluster counts.
Symptom: PARalyzer cluster count 5-100x off from literature reports for the same RBP.
Fix: Use the PARalyzer default parameters (Corcoran 2011), tuned for that RBP class. Validate on a known-binding region with a reference dataset before publication.
Trigger: HITS-CLIP aligned with STAR or bowtie2 in standard mode; CIMS finds few deletion sites.
Mechanism: Standard STAR/bowtie2 are aggressive about handling deletions; CIMS expects the deletions to be visible as CIGAR D operations in BAM. STAR/bowtie2 may soft-clip or fail to align deletion-bearing reads.
Symptom: Few CIGAR D operations in BAM (samtools view dedup.bam | awk '$6 ~ /D/' | wc -l); CIMS deletion site count low.
Fix: Re-align HITS-CLIP with BWA-aln (Zhang lab / CTK convention) or STAR --scoreDelOpen -1 --scoreDelBase -1 --scoreInsOpen -1 --scoreInsBase -1 to permit deletions. Or use Novoalign which is more deletion-tolerant.
Trigger: PAR-CLIP aligned with STAR --outFilterMismatchNoverReadLmax 0.04; T->C reads discarded.
Mechanism: PAR-CLIP per-T conversion rate 20-50% means a 30 nt read with 8 Ts may have 4 T->C events = 13% mismatch rate, exceeding the 4% ceiling.
Symptom: 40-70% read loss at alignment for PAR-CLIP; downstream T->C site detection finds nothing.
Fix: Raise to 0.07 for PAR-CLIP only (see clip-seq/clip-alignment).
Trigger: Single-end CLIP; using read 5' end as CL site without strand consideration.
Mechanism: For plus-strand RNA, the cDNA 5' end is downstream of the CL position. For minus-strand RNA, it is upstream. Without strand-aware coordinate conversion, half of CL sites are mis-positioned by ~1 nt.
Symptom: mCross / motif analysis shows the motif positioned 1 nt off from expected.
Fix: Verify the BED output handles strand correctly. CTK CITS, PureCLIP, and most modern tools do this automatically; custom scripts must add if strand == '-': cl_position = read_end_5p + 1.
| Scenario | Tool | Parameters |
|---|---|---|
| Single-nt CL map for mCross motif registration | PureCLIP | -i dedup.bam -ibam sminput.bam -dm 8 |
| iCLIP/eCLIP CITS truncation sites | CTK CITS | tag2cluster.pl -cs5 5 -m 1 |
| HITS-CLIP deletion CIMS | CTK CIMS | CIMS.pl -big -c -p 0.01 |
| PAR-CLIP T->C clusters | PARalyzer | Per-RBP params tuned from Corcoran 2011 defaults |
| PAR-CLIP T->C single-nt | CTK CIMS substitution | CIMS.pl -type sub -nuc t -mut c -p 0.001 |
| Yeast CRAC | pyCRAC | pyCRAC.py with HTP-tagged protein |
| Variant effect at CL sites | PureCLIP + DeepRiPe | See clip-seq/clip-deep-learning |
| Allele-specific binding | WASP-filtered BAM + PureCLIP | See clip-seq/clip-alignment for WASP |
| Cross-CLIP comparison | PureCLIP (consistent across variants) | Same parameters |
| m6A miCLIP2 sites | miCLIP2-specific (m6Aboost) | See clip-seq/m6a-clip |
| STAMP edit sites | Not crosslink-based | See clip-seq/stamp-antibody-free |
| Pattern | Likely cause | Action |
|---|---|---|
| PureCLIP << CTK CITS site count | PureCLIP HMM very focal; CITS empirical broader | Both correct; report which threshold |
| PARalyzer clusters << CIMS T->C sites for PAR-CLIP | PARalyzer is cluster-level; CIMS is single-nt | Aggregate CIMS to clusters for comparison |
| PureCLIP CL sites at unexpected positions | Strand mis-assignment OR aligner soft-clip | Check BED strand column; verify --alignEndsType EndToEnd |
| HITS-CLIP CIMS empty | Aligner not deletion-tolerant | Re-align with BWA-aln or STAR with adjusted scoring |
| PAR-CLIP CIMS << expected | Reads lost at mismatch ceiling | Raise STAR --outFilterMismatchNoverReadLmax to 0.07 |
| eCLIP CITS positions shifted by 1 nt | Strand handling off-by-one | Verify R2 5' end position handling |
| Multiple CITS sites within 5 nt | RT stops near each other; same CL event | Cluster within 10 nt window post-detection |
| Motif registers 5 nt off in mCross | CL positions wrong by RT-stop offset | Confirm tool reports "CL - 1" position consistently |
Operational rule: For motif registration and ASB, run PureCLIP with SMInput. For ENCODE-comparable truncation-based output, also run CTK CITS. Cross-validate by checking that mCross motif PWM is the same when fed PureCLIP sites vs CTK CITS sites. If they diverge by > 2 nt in motif position, suspect strand or off-by-one issue.
# Step 1: PureCLIP single-nt sites
pureclip \
-i sample.dedup.bam -bai sample.dedup.bam.bai \
-g genome.fa \
-ibam sminput.dedup.bam -ibai sminput.dedup.bam.bai \
-o sample.crosslinks.bed \
-or sample.regions.bed \
-nt 8 -dm 8 -iv expressed_tx.bed
# Step 2: mCross motif registration
mCross -i sample.crosslinks.bed -g genome.fa -k 7 -n 5 -o mcross_out
# Step 3: Intersect with heterozygous SNPs for allele-specific binding
bedtools intersect -wa -wb -s -a sample.crosslinks.bed -b het_snps.vcf > cl_at_hets.bed
# Step 4: Test allele bias with BEAPR or ASPRIN
# (see allele-specific CLIP literature; not in this skill)| Error / symptom | Cause | Solution |
|---|---|---|
| PureCLIP "Convergence not reached" | HMM didn't converge on sparse coverage | Restrict to expressed transcripts with -iv expressed.bed |
| PureCLIP > 24h runtime | Full genome on large library | Test on chr22 first; add -iv filter |
| CTK CIMS empty for HITS-CLIP | Aligner not deletion-tolerant | Re-align with BWA-aln |
| CITS truncation sites not single-nt | CIGAR S operations from soft-clip | Verify --alignEndsType EndToEnd upstream |
| PAR-CLIP CIMS empty | Reads lost at mismatch ceiling | Raise STAR mismatch tolerance |
| Off-by-one motif position | Strand handling differs | Verify tool documents whether output is CL or CL-1 |
| Single-nt motif lost in HOMER on PureCLIP sites | Site BED too narrow; need flanking | Extend bedtools slop -b 15 before motif analysis |
| mCross "no crosslinks found" | Passed peak BED instead of CL BED | Use single-nt site output |
| PureCLIP output looks like uniform distribution | R2 5' end trimmed in preprocessing | Re-preprocess; -g and --trim_front2 banned for CLIP |
| Strand-specific motif inverted | BED column 6 wrong | Verify strand encoding; PureCLIP preserves correctly |
© GPTomics, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
SKILL.md and 2 other files in clip-seq/crosslink-site-detection of GPTomics/bioSkills.
Open the folder on GitHubat commit d91ed3d
We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in GPTomics/bioSkills, which our catalogue first saw on October 7, 2026.
Bio Clip Seq Crosslink Site Detection next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Bio Clip Seq Crosslink Site Detection this skillGPTomics/bioSkills | 1.2k | 2 repos | ~5k | Automated safety check: Pass | MIT | |
| Alphagenome Single Variant Analysisgoogle-deepmind/science-skills | 3.2k | 2 repos | ~3k | Automated safety check: Notes | Apache-2.0 | |
| 13C Metabolic Flux AnalysisK-Dense-AI/scientific-agent-skills | 48k | 1 repos | ~3.2k | Automated safety check: Pass | MIT | |
| Clinvar Databasegoogle-deepmind/science-skills | 3.2k | 2 repos | ~3.9k | Automated safety check: Notes | Apache-2.0 | |
| Metabolic Study Planneraiming-lab/AutoResearchClaw | 15k | — | ~1.9k | Automated safety check: Pass | MIT | |
| Dbsnp Databasegoogle-deepmind/science-skills | 3.2k | 2 repos | ~3.4k | Automated safety check: Notes | Apache-2.0 |
google-deepmind/science-skills
Analyzes genetic variant effects on gene expression (RNA-seq), chromatin accessibility (DNASE), histone marks (ChIP), and transcription factors using the AlphaGenome API.
K-Dense-AI/scientific-agent-skills
Estimates reaction fluxes inside cells from steady-state carbon-13 labeling data with a bundled mfapy-based solver, and reports which fluxes the data pin down.
google-deepmind/science-skills
A skill your agent uses when needing clinical significance, pathogenicity classifications (e.g., Pathogenic, Benign, VUS), clinical evidence rationales, or finding "hard positive" benchmark controls…
aiming-lab/AutoResearchClaw
Turns a broad metabolic modelling topic into a concrete, paper-shaped plan with organism, model, perturbations, metrics and figures before any FBA code is written.
google-deepmind/science-skills
A skill your agent uses when you want to look up, map, and search for short genetic variants (SNPs, indels) in NCBI's dbSNP database.
aiming-lab/AutoResearchClaw
Runs a metabolic flux analysis from model loading to phenotype prediction and figures by handing work to four sub-agents in sequence.
GPTomics/bioSkills
Read, write, and convert multiple sequence alignment files using Biopython Bio.AlignIO.
GPTomics/bioSkills
Installs the bioSkills collection of 425 bioinformatics skills in one step, or only chosen categories, so sequencing, RNA-seq, single-cell and variant tasks get specialized help.
GPTomics/bioSkills
Write biological sequences to files (FASTA, FASTQ, GenBank, EMBL) using Biopython Bio.SeqIO.
GPTomics/bioSkills
Soft- or hard-clips PCR primer footprints from aligned amplicon BAMs so primer bases stop masquerading as confirmed reference sequence.
GPTomics/bioSkills
Filters BAM alignments by FLAG bits, mapping quality and regions with samtools view or pysam, with recipes for common keep and drop cases.
GPTomics/bioSkills
Create and use BAI/CSI indices for BAM/CRAM files using samtools and pysam.
Categories
Detect single-nucleotide crosslink (CL) sites in CLIP-seq data using truncation patterns (iCLIP/eCLIP CITS), crosslink-induced mutations (HITS-CLIP CIMS deletions, PAR-CLIP T-to-C), or…. Bio Clip Seq Crosslink Site Detection is an agent skill from GPTomics/bioSkills. Detect single-nucleotide crosslink (CL) sites in CLIP-seq data using truncation patterns (iCLIP/eCLIP CITS), crosslink-induced mutations (HITS-CLIP CIMS deletions, PAR-CLIP T-to-C), or HMM/kernel-density methods (PureCLIP, PARalyzer, CTK).
Bio Clip Seq Crosslink Site Detection fits situations like: single-nucleotide resolution is required for motif registration (mCross); allele-specific binding (BEAPR); variant-effect prediction; comparing crosslink chemistry across CLIP variants.
Run `npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a claude-code`. Or copy the skill folder (clip-seq/crosslink-site-detection in GPTomics/bioSkills) into .claude/skills/bio-clip-seq-crosslink-site-detection in your project. Claude Code loads it when a task matches its description.
Run `npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a codex`. Or copy the skill folder (clip-seq/crosslink-site-detection in GPTomics/bioSkills) into .agents/skills/bio-clip-seq-crosslink-site-detection in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add GPTomics/bioSkills --skill bio-clip-seq-crosslink-site-detection -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/bio-clip-seq-crosslink-site-detection, .gemini/skills/bio-clip-seq-crosslink-site-detection, .github/skills/bio-clip-seq-crosslink-site-detection and .opencode/skills/bio-clip-seq-crosslink-site-detection in your project.
Going by SKILL.md and its folder, Bio Clip Seq Crosslink Site Detection needs a shell for the scripts in its folder and the command-line tools its instructions call (pip). Our summary lists: Python 3; A Bash shell.
SKILL.md contains no URLs. Its commands use pip, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
Bio Clip Seq Crosslink Site Detection is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
About 5k tokens (SKILL.md is roughly 20k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
Skills that share tags, products or a category with Bio Clip Seq Crosslink Site Detection: Alphagenome Single Variant Analysis (google-deepmind/science-skills, 3.2k stars), 13C Metabolic Flux Analysis (K-Dense-AI/scientific-agent-skills, 48k stars), Clinvar Database (google-deepmind/science-skills, 3.2k stars) and Metabolic Study Planner (aiming-lab/AutoResearchClaw, 15k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
GPTomics (a GitHub organization) maintains it in GPTomics/bioSkills, which has 1,218 GitHub stars. The repository holds 559 skills in this directory. The repository was last updated on August 15, 2026.
Source: GPTomics/bioSkills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.