Toggle SELEX Services

Unlock Complex Targets with Our Advanced Toggle SELEX Services

At KMD Bioscience, we push the boundaries of aptamer discovery. Traditional SELEX (Systematic Evolution of Ligands by EXponential enrichment) can face challenges with targets that are difficult to immobilize, have low solubility, or require recognition under specific physiological conditions. Our proprietary Toggle SELEX platform provides a powerful, flexible solution to overcome these hurdles and deliver high-affinity, high-specificity aptamers for your most demanding targets.

What is Toggle SELEX?

Toggle SELEX is an intelligent, counter-selection strategy that evolves aptamers through alternating selection pressures. Instead of selecting solely for binding to your target, the process dynamically toggles between:

1. Positive Selection: Enriching nucleic acid libraries that bind to your primary target.

2. Negative Selection (Counter-Selection): Actively removing sequences that cross-react with closely related molecules, non-target isoforms, or the immobilization matrix itself.

This iterative “on/off” selection creates a powerful filtering mechanism, driving the evolution of aptamers with exceptional specificity and minimizing off-target binding.

Our Toggle SELEX Advantage: Precision by Design

We customize the toggle parameters to fit your exact needs, making it ideal for:

• Discriminating Between Highly Similar Targets: Isolate aptamers that distinguish between protein family members (e.g., kinase isoforms), mutant vs. wild-type proteins, or phosphorylated vs. non-phosphorylated states.

• Targeting Membrane Proteins & Complex Antigens: Use cell-based SELEX, toggling selection between target-expressing cells and non-expressing or mock-transfected cells to find aptamers against native membrane protein conformations.

• Solving Immobilization Challenges: For targets that lose activity or conformation when bound to a solid support, we use solution-phase Toggle SELEX, toggling against the capture matrix.

• Developing Therapeutic & Diagnostic Aptamers: Ensure your aptamer binds only to the disease-specific epitope by toggling against healthy tissue or serum components, enhancing safety and diagnostic accuracy.

Our End-to-End Toggle SELEX Workflow

1. Consultation & Design: Our experts work with you to define the target and, critically, the optimal counter-targets for the toggle process.

2. Library & Preparation: We design and synthesize sophisticated random oligonucleotide libraries and prepare highly pure target/counter-target molecules.

3. Iterative Toggle Selection: Our automated, high-fidelity platform performs the cyclic process of binding, partitioning, elution, and amplification, seamlessly integrating positive and negative selection rounds.

4. High-Throughput Sequencing (NGS) & Bioinformatics: We employ NGS to analyze enriched pools and use advanced bioinformatics to identify consensus families and promising candidate sequences.

5. Characterization & Validation: Top candidates are synthesized and rigorously validated for affinity (SPR, BLI), specificity (ELISA, flow cytometry), and function (neutralization, inhibition assays).

6. Delivery & Reporting: You receive fully characterized aptamer sequences, comprehensive binding data, and a detailed project report.

Why Partner with KMD Bioscience for Toggle SELEX?

• Deep Expertise: Scientists skilled in designing sophisticated selection strategies for complex biological questions.

• Proven Platform: A track record of successful aptamer discovery against challenging targets, including GPCRs, ion channels, and specific cell populations.

• State-of-the-Art Facilities: Integrated workflows from molecular biology, NGS, to biophysical analysis under one roof.

• Customized & Confidential: Fully bespoke projects with complete IP protection—you own the resulting aptamers.

Applications of Toggle SELEX-Derived Aptamers

• Targeted Therapeutics & Drug Delivery

• High-Precision In Vitro Diagnostics (IVD)

• Advanced Imaging & Biosensing Probes

• Critical Reagents for Cell Sorting & Purification

Ready to toggle your aptamer discovery to the next level?

Contact our SELEX specialists today to discuss how our Toggle SELEX service can unlock the potential of your challenging target. Let’s develop the precise molecular tools your research or product requires.