BID-Seq: Quantitative Pseudouridine Mapping at Single-Base Resolution Without Antibodies
Uncover transcriptome-wide pseudouridine (Ψ) modifications with base-level precision using CD Genomics' BID-Seq platform. This bisulfite-induced deletion sequencing method offers unmatched sensitivity, single-base resolution, and absolute quantification—without antibodies or enzymes. Whether you're investigating mRNA stability, stop codon readthrough, or writer protein dynamics, BID-Seq empowers your RNA epitranscriptomics research with clarity and confidence.
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Accurate
Scalable
Publication-ready
Why Understanding Pseudouridine (Ψ) Modifications Requires BID-Seq
Pseudouridine (Ψ) is one of the most abundant and evolutionarily conserved RNA modifications, long studied in rRNA and tRNA. Yet in messenger RNA (mRNA), where its role may be equally critical, it remains poorly characterized—not due to lack of biological importance, but because of the limitations of existing detection technologies.
Standard pseudouridine mapping methods such as Ψ-seq and CeU-seq rely on indirect chemistry or antibody enrichment, providing low resolution, high background, or incomplete coverage. They fail to answer two essential questions for RNA biologists and transcriptomic researchers:
- Where exactly is pseudouridine located in mRNA, at single-nucleotide resolution?
- How much of a transcript is modified at a given site, and how does this vary by condition or cell type?
Without answers to these, understanding the functional consequences of Ψ on mRNA splicing, translation, decay, or stop codon dynamics remains speculative.
BID-Seq Enables Base-Level Clarity, Quantification, and Confidence
BID-Seq—short for Bisulfite-Induced Deletion Sequencing—is the first technology to overcome these barriers. Instead of relying on RT termination or enrichment, BID-Seq exploits a chemically precise conversion of Ψ into a reverse transcription–induced deletion signal, producing clear, quantifiable, and highly reproducible markers of pseudouridine at single-base resolution.
This enables researchers to:
- Quantify modification stoichiometry across conditions and tissues
- Detect dynamic changes in pseudouridylation in response to stress, disease, or differentiation
- Map endogenous Ψ in critical regions, including CDS, 3′ UTRs, and stop codons
- Associate specific PUS enzymes with modification profiles using knockdown or knockout models
Why It Matters Now
As RNA modification research shifts from static catalogs to functional regulation, the ability to resolve pseudouridine quantitatively and spatially becomes essential. With BID-Seq, researchers are finally equipped to explore Ψ as a true regulatory mark—on par with m6A—in both basic and translational transcriptomics.
How BID-Seq Works – From Chemistry to Confidence
At the heart of BID-Seq is a chemically precise transformation of pseudouridine (Ψ) into a detectable signal during reverse transcription—without compromising sequence complexity or requiring any enrichment.
Step 1: Selective Ψ Conversion at Neutral pH
Unlike conventional bisulfite protocols that aggressively deaminate cytosine (C→U), BID-Seq employs neutral pH bisulfite chemistry that selectively reacts with pseudouridine to form a Ψ–BS adduct. This optimized environment preserves unmodified bases, maintaining the full complexity of the RNA sequence for accurate downstream analysis.
Step 2: Deletion Signal During Reverse Transcription
The Ψ–BS adduct causes reverse transcriptase to skip a base during cDNA synthesis—creating a reproducible single-nucleotide deletion at the modification site. This deletion event forms the molecular "signature" of Ψ, uniquely distinguishable from sequencing errors or structural noise.
Step 3: Base-Resolution Detection and Quantification
Using calibrated synthetic RNA libraries and motif-aware models, deletion frequencies are interpreted as quantitative measures of pseudouridylation stoichiometry—not just presence/absence. The approach supports:
- Absolute modification fraction calculations
- Detection of dynamic changes across conditions
- Motif enrichment and writer protein assignment
- Mapping Ψ in CDS, UTRs, and stop codons with high confidence
How BID-Seq Compares to Other Pseudouridine Sequencing Methods
Understanding what sets BID-Seq apart requires a look at the current limitations in the field. Conventional Ψ mapping methods fall into two categories: termination-based detection (e.g., Ψ-seq, Pseudo-seq) and enrichment-based detection (e.g., CeU-seq). Each has critical trade-offs.
| Method | Resolution | Quantitative | Background Interference | Enrichment Required | Limitation |
|---|---|---|---|---|---|
| Ψ-seq / Pseudo-seq | Low | ❌ | High (RT noise, false stops) | Yes (CMC) | Inconsistent between datasets |
| CeU-seq | Medium | ❌ | Moderate | Yes (biotin enrichment) | No stoichiometry or base-level mapping |
| Bisulfite-Seq (standard) | N/A | ❌ | High (C→U dominates) | No | Fails to detect Ψ reliably |
| BID-Seq | Single-base | ✅ | Minimal | No |
Why BID-Seq Is the Preferred Choice
- Truly quantitative: Deletion signal reflects actual modification fraction
- Unambiguous detection: Base-resolution calling, not motif-based inference
- No antibody dependency: Eliminates variability from commercial reagents
- High sample compatibility: Works with low-input RNA and diverse tissues
- Designed for publication: Based on peer-reviewed protocol (Nat Biotechnol)
Service Workflow – From Sample to Results
Our BID-Seq service is designed as a full-scope, researcher-friendly workflow—from sample submission to bioinformatic insights—so you can focus on interpreting your findings, not managing technical details.
Our team remains available to support any downstream analysis, publication preparation, or experimental follow-up.
Bioinformatics & Data Analysis – From Signal to Scientific Insight
BID-Seq doesn't stop at sequencing—it transforms chemical deletion signals into high-resolution, interpretable RNA modification maps. Our integrated bioinformatics pipeline ensures your data is not only clean and accurate, but also biologically meaningful.
Core Data Outputs
- Ψ site identification at single-nucleotide resolution
- Deletion-based quantification of modification fraction
- Transcriptome-wide Ψ profiling: including CDS, UTRs, and stop codons
- Comparison across conditions, tissues, or knockdown models
Annotation & Contextualization
Each pseudouridine site is annotated with:
- Transcript features (CDS, 3′UTR, exon/intron boundaries)
- Associated motif context (e.g., GUΨCN, poly-U, ΨGA near stop codons)
- Predicted or validated PUS writer enzymes based on existing models or user-provided knockdown data
- Ψ fraction (stoichiometry) at site and transcript levels
Visualizations Included
We provide clean, publication-ready outputs to help you interpret and present your results:
- IGV-compatible tracks for Ψ-site overlay on genome browsers
- Heatmaps of modification fraction across samples or conditions
- Metagene plots showing regional Ψ distribution
- Motif enrichment plots and position weight matrices
- Scatter and volcano plots for condition-specific Ψ dynamics
Optional Add-On Analyses
- Correlation with gene expression (RNA-seq) or mRNA half-life
- Ψ modification clustering for cell type or tissue classification
- Integration with functional annotations: GO, KEGG, or pathway mapping
- Support for custom writer–target validation and experimental design
Whether you're profiling Ψ under stress, mapping dynamic regulation, or validating the function of a PUS enzyme, our analytical workflows help you move from data to discovery—with clarity, speed, and confidence.
Applications – Where BID-Seq Delivers Scientific Value
BID-Seq is more than a sequencing solution—it's a platform for discovery. Whether you're exploring the landscape of RNA modifications or dissecting their functional impact on gene regulation, BID-Seq empowers you with actionable insights at single-base precision.
Build comprehensive pseudouridine atlases in various biological systems:
- Human or mouse cell lines
- Primary tissues across organs or developmental stages
- Model organisms or engineered cell types
Quantify and localize Ψ in CDS, 3′UTRs, and stop codons—regions often linked to RNA stability and translation efficiency.
Use BID-Seq to study Ψ modification dynamics under diverse biological conditions:
- Cellular stress (e.g., heat shock, oxidative stress)
- Immune activation and cytokine exposure
- Differentiation, senescence, or tumor transformation
- Environmental or chemical perturbations
Track condition-specific shifts in Ψ stoichiometry with base-level resolution.
Validate pseudouridine synthase (PUS) targets via:
- RNA profiling in PUS knockout or knockdown models
- Assigning Ψ sites to specific enzymes (e.g., TRUB1, PUS7, PUS1)
- Linking motifs (e.g., GUΨCN, poly-U) to enzyme activity
Correlate enzyme loss with quantitative changes in Ψ at defined positions.
Link Ψ modification with post-transcriptional regulation:
- Analyze mRNA half-life changes associated with Ψ-enriched transcripts
- Study how Ψ influences mRNA decay rates, translation efficiency, or localization
- Integrate BID-Seq with RNA-seq to infer Ψ-dependent expression dynamics
Investigate a unique regulatory role of pseudouridine:
- Identify Ψ-modified stop codons (ΨGA, ΨAA, ΨAG motifs)
- Quantify readthrough efficiency under natural or engineered conditions
- Assess implications for protein isoform diversity or coding potential
Use BID-Seq to uncover Ψ-based biomarkers:
- Map tissue-enriched or cell-type–specific Ψ patterns
- Discover altered Ψ profiles in disease models (e.g., cancer, neurodegeneration)
- Explore mitochondrial mRNA pseudouridylation and its functional implications
Sample Requirements – What You Need to Get Started
| Sample Type | Minimum Amount | Notes |
|---|---|---|
| Whole blood | > 2 mL | Use EDTA tubes only. Heparin is not compatible. |
| Cultured cells | > 5 × 106 cells | Cell pellets preferred. |
| Tissue | 100 mg | Fresh or frozen. Avoid necrotic material. |
| Total RNA | > 10 µg | OD260/280: 1.6–2.3; No visible degradation. |
Shipping Instructions
- Place sample in a 1.5 mL RNase-free microcentrifuge tube
- Seal with parafilm or cap lock
- Ship on dry ice with adequate insulation
Storage Guidelines
- Cells / tissues: Preserve in TRIzol or RNA stabilization solution; snap freeze in liquid nitrogen and store at –80 °C
- RNA: Resuspend in ethanol or RNase-free ultrapure water; store at –80 °C; avoid freeze–thaw cycles
For other sample types or low-input projects, please contact us for custom recommendations.
Why Choose CD Genomics
At CD Genomics, we understand that RNA modification research demands more than just sequencing—it requires precision, reproducibility, and domain-specific insight. That's why we've built our BID-Seq platform not just as a technology offering, but as a research-enabling partnership.
Our BID-Seq workflow is grounded in the original protocol published in Nature Biotechnology—recognized for enabling the first base-resolution, quantitative mapping of mRNA pseudouridines. We've optimized it for service scalability without compromising data integrity.
From sample QC and bisulfite chemistry to deletion-calling pipelines and transcriptomic annotation, every step is performed in-house by teams who specialize in RNA modification biology. This ensures end-to-end control and consistent quality.
We go beyond raw site calling—our analysis highlights transcript-region specificity, motif context, writer enzyme association, and condition-dependent Ψ dynamics. That means your data is ready to support hypothesis generation, figure preparation, or publication.
Whether working with rare primary cells, low-yield RNA, or custom model systems, BID-Seq adapts. We offer protocol adjustments and expert consultation to accommodate your study design.
We understand that your project doesn't end with data delivery. Our team is available to answer follow-up questions, assist with downstream interpretation, or help design validation strategies. You're never left decoding your results alone.
