Software

iGEM Criteria

Overview

ASO Designer is an open-source platform that helps researchers design and rank antisense oligonucleotides (ASOs) for targeted RNA knockdown. It combines sequence analysis, structural modeling, cellular context, and machine learning to predict which ASOs are most likely to succeed in living cells.
Unlike simple GC% or melting temperature calculators, ASO Designer integrates:

  • RNA accessibility & secondary structure
  • RNase H1 cleavage compatibility
  • Transcript abundance & half-life in the chosen cell line
  • Expression-weighted off-target risk
  • Thermodynamics and hybridization energy
  • Optional custom features such as the codon adaptation index (CAI)

The system uses a learning-to-rank model trained on experimental inhibition data to prioritize the most promising sequences.

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Motivation

Gene Silencing and downregulation is a fundamental approach in research, medicine, and specifically synthetic biology. By selectively reducing the expression of specific genes, scientists can uncover their biological roles, validate therapeutic targets, and engineer new cellular behaviors. Unlike genome-editing tools such as CRISPR, which introduce permanent changes to the DNA sequence, silencing and downregulation provide a transient and reversible modulation of gene activity. This temporal control allows researchers to investigate gene function without altering the genome itself, offering a safer and more flexible strategy for both experimental and therapeutic applications. In research, silencing enables functional genomics studies, exploration of antibiotic resistance mechanisms, metabolic engineering of synthetic pathways, and other synthetic biology applications where fine-tuning gene expression is essential. In medicine, targeted silencing of disease-associated genes has led to major breakthroughs in treating genetic disorders, cancers, and viral infections. Antisense oligonucleotides (ASOs) are among the most versatile and clinically advanced tools for gene silencing, with several FDA-approved therapies already demonstrating their precision and efficacy [1].

Designing effective antisense oligonucleotides (ASOs) is still largely a trial-and-error process. Many sequences that look promising in silico fail in cells because they ignore cell-specific context, RNA structure and accessibility, RNase H1 cleavage windows, transcript abundance and half-life, and expression-weighted off-targets. Existing tools often optimize one or two factors (e.g., GC% or ΔG) in isolation, making it hard for wet-lab teams to prioritize candidates with a high probability of in-cell success and to reproduce results across labs and datasets.


ASO Designer was built to close this gap. It unifies thermodynamics and hybridization modeling with cell-line aware features and a rank model trained on large experimental inhibition datasets, producing ranked, interpretable ASOs rather than single opaque scores. By using standard formats (FASTA/GFF/GTF), shipping an open-source package and a simple web UI, and logging run configurations for reproducibility, ASO Designer reduces experimental cycles and cost, enables transparent decision-making, and makes advanced ASO design accessible to both iGEM teams and research groups integrating RNA therapeutics or synthetic-lethality screens into their pipelines.

Who is it For?

Our Audience

  • Wet-lab teams designing knockdowns without coding expertise.
  • iGEM groups and academic researchers need a transparent, reproducible workflow.
  • Labs want results in formats ready for ordering or downstream analysis.

Audience Size Analysis

Our estimates for the addressable research community for the ASO Designer software tool comprise roughly 12,930–26,100 potential users worldwide. This estimate encompasses ~630–945 academic institutions. According to the World Higher Education Database (WHED) [2], there are around 21,000 universities globally, of which approximately 30% host life-science programs and 10–15% conduct ASO-related work. According to GlobalData [3], around 285 industry organizations develop or test antisense therapeutics. With an average of 4–6 active users per academic lab, and ~4 labs per institute, and 10–12 per company, the expected user base spans around 13,000 researchers on the conservative end to ≈26,000 on the generous end.

Importantly, the tool could also benefit a significant number of iGEM teams working in synthetic biology, genetic regulation, and RNA-based design. Each year, over 400 iGEM teams participate worldwide, many exploring gene control, RNA therapeutics, or modular chassis engineering, areas where ASO Designer provides a ready-to-use, open-source solution for rational oligonucleotide design and target validation. Similar to the success of CRISPR-Cas systems in revolutionizing genetic research, our tool harnesses ASO technology to provide an equally powerful yet complementary approach for investigating gene knockdown effects. By streamlining the process of targeted gene silencing, this platform becomes an essential resource that expands the synthetic biology toolkit, offering researchers a versatile and accessible method for exploring gene function and regulatory networks.

Because ASO Designer is open-source, English-based, and browser-accessible, it can serve nearly all of this niche from launch without localization barriers. At the beta stage, realistic engagement is expected from 1–3% of the reachable pool, between 100-1,000 early adopters, sufficient to collect statistically meaningful feedback and benchmark usability.

How TAUSO Works

The TAUSO pipeline integrates biological knowledge, structural modeling, and machine learning to transform a target gene sequence into a set of experimentally viable antisense oligonucleotide (ASO) candidates. Starting from user inputs such as organism and target gene, the system automatically retrieves genomic references, normalizes exon–intron annotations, and generates multiple ASO candidates in parallel chemistry modes. Each candidate is analyzed through a comprehensive feature computation pipeline encompassing thermodynamic stability, RNA accessibility, codon usage bias, and contextual environment. These features feed into a learning-to-rank model, trained on real inhibition data, which scores each sequence by predicted efficacy. Subsequent off-target assessment, intelligent shortlisting, and exportable reports ensure that every user receives high-confidence ASOs ready for experimental testing or further computational refinement.

Comparison To Competitors

Although several computational tools for antisense oligonucleotide (ASO) design have been developed in recent years, none of them fully capture the biological reality of ASO activity. Most existing platforms focus on isolated aspects of the design process, such as only optimizing chemical modifications, relying on minimal features like accessibility or hybridization, or providing annotations without empirical scoring.

Our platform was created to address this gap.
We addressed these limitations by improving the accuracy of accessibility and hybridization features, incorporating novel descriptors from literature, and basing our model on empirical data to ensure realistic biological relevance. We developed a comprehensive, machine learning-driven, and biologically aware framework that expands beyond conventional design logic by incorporating new experimental and structural datasets unavailable in existing tools, including:

  • RNase H cleavage profiles , representing real enzymatic preferences and cleavage efficiency.
  • RNA-binding protein (RBP) interaction maps, reflecting post-transcriptional competition and stability effects.
  • Enhanced folding and hybridization modeling, improving the predictive power of structural accessibility metrics.
  • In addition, our model integrates a broad set of structural and sequence-derived features, including codon usage bias, local folding metrics, thermodynamic asymmetry, and region-specific composition, systematically combined and empirically validated within a unified framework.

By combining these complementary biological layers within a machine learning model trained on empirical data, Oncoligo transforms ASO design from a rule-based task into a predictive, biologically validated discovery process.

The table below illustrates how Oncoligo improves upon and outperforms each existing ASO design tool. While all current platforms contribute valuable functionalities, they remain limited in scope, empirical depth, or generalizability. Oncoligo overcomes these limitations by integrating experimental data, enhanced folding and hybridization modeling, and ML-based prioritization into one unified and reproducible design pipeline-delivering more accurate, biologically meaningful, and scalable results.

Model Strength Limitation Our Added Value
ASOptimizer Deep learning, optimizes modifications [4] Optimizes given sequence only Integrated sequence finding with multiple features
PFRED Rich annotations (exon, SNPs, conservation) [5] No prioritization, manual analysis Empirical automated ranking pipeline
QIAGEN LNA GapmeR Designer LNA optimization [6] Narrow scope, rule-based Generalizable & empirical multi-step framework
LNCASO long non-coding RNAs-specific design [7] Not generalizable, data undisclosed Broad applicability & reproducible

Table 1: This table summarizes the main strengths and limitations of current computational platforms for antisense oligonucleotide design and highlights how Oncoligo surpasses each of them. While existing tools focus on specific aspects - such as modification optimization or annotation visualization - Oncoligo integrates machine learning, empirical data, and structural modeling into a unified, biologically informed framework that delivers superior generalizability and predictive accuracy.


Altogether, Oncoligo provides a superior and more reliable approach to ASO design - bridging the gap left by current tools and setting a new standard for predictive accuracy.

You can learn more about the computational foundations of our framework in the dedicated Model Page, where we describe the model’s architecture, feature integration, and predictive principles in detail.

User's Guide

First Step

Organism Input

Select the organism and reference build you’re working with. This choice determines the transcriptome, isoforms, and expression tables used later for off-target analysis and coverage calculations, so it must match your experiment (for example, Human - GRCh38; Yeast - S288C). After picking exactly one organism, continue to the next step.

first step

Second Step

Gene Input

Provide the gene you want us to analyze. You can either choose the Gene by its Canonical Name, upload a FASTA/GenBank file, or paste the sequence directly into the text box. What you enter here defines the search space for candidate ASOs; longer inputs explore more sites and may take a little longer to process.

second step

Third Step

Numeric Parameters

To get a more customized result sheet, the Top-k results is a numeric input field (default = 10) specifying how many optimized ASOs will be returned. Get detailed analysis: checkbox enabling an extended output with off-target detail analysis.

Third step

Fourth Step

Contact Information & Start

Confirm where we should send your results. Enter your name and a valid email address, then click Start Processing. You will receive a confirmation email that the processing has begun. Your job is queued on the server, and when it finishes, you’ll receive the result page by mail.

FAQ - ASO Designer

What is ASO Designer?

ASO Designer is a user-friendly tool for designing antisense oligonucleotides (ASOs) to silence specific genes. It uses advanced algorithms to suggest sequences that are efficient, specific, and practical for research use.

Which organisms are currently supported by the ASO Designer tool?

The ASO Designer currently supports human, mouse and yeast gene knockdown. E. coli is going to be available in the next software update. If you’re working with another species, feel free to email us at igem@tauex.tau.ac.il to request support in future updates.

How long does it usually take to get results?

Most jobs are completed within a few minutes to about 30 minutes. Runtime depends on gene length, organism, structural complexity, and server availability.

What factors determine the best ASOs that are generated?

We rank candidates using multiple criteria, including binding energy (target pairing strength), RNA folding/accessibility, GC content (stability balance), off-target predictions, and additional model features. This combination helps surface ASOs that are both effective and practical.
For further reading visit our Model page - Methods section.

Does ASO Designer guarantee experimental success?

No computational tool can guarantee success. ASO Designer provides high-quality predictions to save time and resources, but all candidates should be validated experimentally.

What if my gene is not found in the database?

You can upload your own FASTA sequence, and ASO Designer will design ASOs directly from that input, no need to rely solely on built-in databases.

Can I design ASOs for non-coding RNAs or lncRNAs?

Yes. ASO Designer works with any transcript sequence, including coding and non-coding RNAs (e.g., lncRNAs).

Do I need advanced bioinformatics skills to use ASO Designer?

No. The interface is designed to be intuitive for researchers, clinicians, and students. You only need the gene or sequence of interest, no coding required.

Is ASO Designer free to use?

Yes. ASO Designer is freely available for academic and research use. Please cite the tool in any publications or presentations that use it.

Who do I contact if I have questions or need help?

We value every user. If you have questions or run into issues, please reach out at igem@tauex.tau.ac.il. Your feedback helps us improve and supports smoother research workflows.

Integration with other tools

Inputs include standard genomics and context files such as FASTA (or GenBank) and GFF/GTF annotations. Outputs include a ranked PDF report together with feature-rich tables for downstream analysis. Interfaces include a simple web UI for point-and-click runs and a PyPI package for local or CI workflows (pip install asodesigner).

Python Package

License & Availability

  • Source code - available in the official iGEM GitLab repository.
  • License - MIT License [8](permissive for reuse).

Citation
ASO Designer: an open-source platform for antisense oligonucleotide design. iGEM Team TAU 2025.

Future Steps

Expand organism support
Add mouse and E. coli as first-class, validated builds, then extend to additional model organisms. Provide strain/build selection and versioned transcriptomes with matching expression tables.

Collaborate with researchers
Partner with iGEM teams and external labs for co-designed case studies, usability testing, and shared benchmark datasets. Establish a feedback loop (issues, surveys, office hours) to prioritize features that unblock real experiments.

References

[1] Collotta, D., Bertocchi, I., Chiapello, E., & Collino, M. (2023). Antisense oligonucleotides: a novel Frontier in pharmacological strategy. Frontiers in pharmacology, 14, 1304342. https://doi.org/10.3389/fphar.2023.1304342
[2] “About – WHED – IAU’s World Higher Education Database.” Accessed: Oct. 06, 2025. [Online]. Available: https://www.whed.net/About.html
[3] “Who are the leading innovators in anti-sense oligonucleotides for the pharmaceutical industry?” Accessed: Oct. 06, 2025. [Online]. Available: https://www.pharmaceutical-technology.com/data-insights/innovators-genomics-anti-sense-oligonucleotides-pharmaceutical
[4] Hwang, G., et al. (2024). ASOptimizer: Optimizing antisense oligonucleotides through deep learning for IDO1 gene regulation. Molecular Therapy – Nucleic Acids, 35(2), 102186. https://doi.org/10.1016/j.omtn.2024.102186
[5] Sciabola, S., et al. (2021). PFRED: A computational platform for siRNA and antisense oligonucleotides design. PLoS ONE, 16(1), e0238753. https://doi.org/10.1371/journal.pone.02387
[6] QIAGEN. (n.d.). Retrieved October 9, 2025, from https://www.qiagen.com/us/knowledge-and-support/knowledge-hub/technology-and-research/lna-technology/antisense-lna-gapmer-design-tool-guide
[7] LNCASO. (n.d.). Retrieved October 9, 2025, from https://iomics.ugent.be/pjdev
[8] “The MIT License – Open Source Initiative.” Accessed: Oct. 06, 2025. [Online]. Available: https://opensource.org/license/MIT