Feature / Client Need |
CLIP-Seq (Standard) |
PAR-CLIP |
RIP-Seq
|
ChIRP / RAP / CHART
|
Resolution |
Single-nucleotide resolution |
Single-nucleotide (enhanced crosslink density) |
Low (region-level, no crosslink site) |
Varies (region-specific, depends on probe design) |
Crosslinking Method |
UV 254 nm (native RNA-protein complexes) |
UV 365 nm + photoactivatable nucleosides (e.g., 4SU) |
No crosslinking (native complexes preserved) |
Formaldehyde (DNA/RNA crosslinking) |
Binding Site Precision |
High (direct crosslinked sites) |
High (with enriched mutation/truncation signatures) |
Moderate (indirect/co-bound RNAs may co-purify) |
Low-to-moderate (depends on probe specificity) |
Requires Antibody |
Yes |
Yes |
Yes |
No (uses probes targeting specific RNA/DNA) |
Target Discovery (Finding Unknown RBPs/RNAs) |
Suitable for transcriptome-wide screening |
Particularly useful for high-turnover RNAs |
Better suited for known RBP targets |
Requires prior knowledge of RNA/DNA targets |
Applicable to Low-Abundance Targets |
Achievable with deep sequencing |
Enhanced crosslinking increases sensitivity |
Often limited by weak or nonspecific enrichment |
Better when targeting abundant lncRNAs or repetitive elements |
Input Requirement |
Medium–High (≥10⁷ cells or ~50 mg tissue) |
High (due to labeling step; requires metabolic activity) |
Low–Medium (≥10⁶ cells) |
Medium–High (depends on RNA abundance) |
Motif Discovery Capability |
Strong, enables sequence and structural motif identification |
Excellent, due to crosslink-induced mutations |
Limited |
Not applicable |
Bioinformatics Complexity |
High; requires crosslink site detection, peak calling, motif analysis |
High; mutation/truncation analysis required |
Low–Moderate; standard RNA-seq pipelines |
Moderate; mapping, enrichment analyses, background removal |
Throughput / Scalability |
High; suitable for genome-wide studies |
High; genome-wide with increased sensitivity |
Moderate; can be transcriptome-wide but prone to noise |
Low–Moderate; focused on specific targets, not genome-wide |
Quantitative Capability |
Moderate–High; allows semi-quantitative binding strength estimation |
High; enables quantification of binding dynamics |
Moderate; influenced by nonspecific signals |
Low; rarely used for quantitative binding assessment |
Specificity / Background |
High; captures direct interactions with minimal background |
High; improved signal-to-noise ratio from photoreactive labeling |
Moderate; high background due to indirect binding |
Low–Moderate; depends on probe design and hybridization stringency |
Compatible with Clinical / Fixed Samples |
Not recommended; requires fresh or quickly frozen samples |
Not compatible; needs metabolic labeling not feasible in clinical tissue |
Sometimes feasible with frozen lysates or IP-ready extracts |
Compatible with FFPE or fixed samples using specialized protocols |
Sample Types |
Cultured cells, fresh/frozen tissue |
Cultured cells only (requires metabolic labeling) |
Cultured cells, frozen or fixed tissues |
Cultured cells, frozen tissues, FFPE, chromatin |
Recommended Controls |
Input RNA, mock IP, knockdown/knockout |
Input RNA, mock IP, knockdown/knockout |
Input RNA, mock IP |
Scrambled probes, input RNA |
Relative Time / Cost |
High; labor-intensive protocol, requires deep sequencing |
High; requires metabolic labeling and specialized reagents |
Low–Moderate; simpler protocol, less expensive |
High; extensive optimization, probe design, and validation required |
Ideal For |
Precise mapping of RBP binding sites transcriptome-wide |
Studying dynamic, high-turnover RNA–RBP interactions |
Validation of known RBP–RNA associations |
Investigating RNA localization, lncRNA function, chromatin association |
Limitations |
Technically demanding; requires large input, deep sequencing, sensitive to RNA degradation |
Limited to cell culture; not applicable to tissues or clinical samples |
Lower resolution; high background; indirect binding complicates interpretation |
Poor resolution; dependent on probe efficiency; requires significant optimization |