/bio-clip-seq-clip-alignment

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Copyright (c) 2026 MD BABU MIA, PhD <md.babu.mia@mssm.edu>

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--- name: bio-clip-seq-clip-alignment description: Align CLIP-seq reads to the genome with crosslink site awareness. Use when mapping preprocessed CLIP reads for peak calling. tool_type: cli primary_tool: STAR measurable_outcome: Execute skill workflow successfully with valid output within 15 minutes. allowed-tools:

• read_file
• run_shell_command

---

CLIP-seq Alignment

STAR Alignment

STAR --runMode alignReads \
    --genomeDir STAR_index \
    --readFilesIn trimmed.fq.gz \
    --readFilesCommand zcat \
    --outFilterMultimapNmax 1 \
    --outFilterMismatchNmax 1 \
    --alignEndsType EndToEnd \
    --outSAMtype BAM SortedByCoordinate \
    --outFileNamePrefix clip_

Bowtie2 Alternative

bowtie2 -x genome_index \
    -U trimmed.fq.gz \
    --very-sensitive \
    -p 8 \
    | samtools view -bS - \
    | samtools sort -o aligned.bam

Post-Alignment Processing

# Index
samtools index aligned.bam

# Deduplicate with UMIs
umi_tools dedup \
    --stdin=aligned.bam \
    --stdout=deduped.bam

Related Skills

• clip-preprocessing - Prepare reads
• clip-peak-calling - Call peaks

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