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Assays and diagnostics

Aptamer Group > Applications > Assays and diagnostics

Novel solutions to enable diverse diagnostic formats.

Specific and sensitive biosensors in just 4 weeks

Bio sensor

Optimer® binders are proven to be compatible with many well-established biosensor techniques for the detection and monitoring of interactions, including:

  • surface plasmon resonance (SPR)
  • bio-layer interferometry (BLI)
  • isothermal titration calorimetry (ITC)

Optimer binders form powerful tools to enable biosensor solutions for diagnostics, wearable sensors, drug monitoring and development and research assays.

Key benefits of Optimer for biosensor applications

  • Highly specific biosensors due to specific target binding of Optimer binders
  • Increased biosensor sensitivity due to the small size of Optimer interactions occur closer to the sensor
  • Potential for novel targeted biosensor assays with the wider target range of Optimer binders
  • Increased signal detection via directed orientation and increased coating density of Optimer binders on biosensor surfaces
  • Shorten your time to market with custom Optimer binders developed in as little as 4 weeks

Using the Optimer platform, highly selective biosensor assays were developed for SARS-CoV-2. Optimer binders were developed for the SARS-CoV-2 S1 protein and showed no interaction with the highly homologous coronavirus S1 proteins within a complex human saliva matrix.

Biolayer interferometry showed Optimer binders specific for SARS-CoV-2 S1 protein were selective for the target in 10% human saliva matrix with no significant interactions with the highly homologous viral targets.

SPR analysis of the small molecule chemotherapeutic, imatinib, showed a concentration-dependent association/dissociation response with the 5’biotinylated imatinib aptamer immobilised on a streptavidin-coated sensor.

BIAcore results show clear target concentration-dependent interactions between the immobilised biotinylated aptamer on a streptavidin-coated chip and the small molecule chemotherapeutic target, imatinib, injected at a flow rate of 30 µL/min to yield a KD=131 ± 11 nM.

Cost-effective, sensitive LFD tests with complete security of supply

Lateral Flow

Optimer® binders are enabling scientists to address the unmet need in the field of point-of-care diagnostics for highly sensitive reagents that can target novel molecules, such as small molecules, enabling novel lateral flow device (LFD) tests for diseases and functions.

We have successfully generated Optimer binders for LFD tests, to offer advantages including

  • the rapid discovery of target-specific reagents in under 4 weeks
  • validation and the coordination of scale-up to enable large-scale operations
  • Optimer matched-pairs and Optimer-antibody pairs for full flexibility in building your LFD

Key benefits of Optimer in LFD tests

  • Cost-effective chemical synthesis methods for scalable LFD tests
  • Increased assay sensitivity due to higher surface coating density
  • Highly stable in LFD test format requiring no cold chain logistics
  • Rapid development times of as little as 4 weeks to enable rapid timelines
  • Excellent batch-to-batch consistency for reproducible results throughout the lifecycle of the diagnostic

Specific, stable Optimer® binders for rapid flow cytometry results

Optimer binders have been successfully developed to a variety of protein and cellular targets to enable novel and improved flow cytometry solutions.

Optimer binders deliver high affinity and target specificity tailored according to the specific assay conditions. This is combined with the flexibility to incorporate the full range of fluorescent labels consistently and cost-effectively for reliable flow cytometry panels that meet your needs.

With rapid Optimer discovery performed in as little as 4 weeks, working with Optimer binders can accelerate your processes to drive discovery through flow cytometry.

Key benefits of Optimer for flow cytometry applications

  • High signal from high specificity of target-specific Optimer binders
  • Reproducible results from standardised and targeted conjugation and batch-to-batch consistency
  • Broad range of targets possible with peptides, proteins and cells
  • Get results faster with full development in as little as 4 weeks

Optimer binders were developed against the human multiple myeloma NCI-H929 cell line, with counter-selection against the leukaemia erythromyeloid K-562 cell line to enable a hypothesis-free biomarker discovery program with therapeutic partners. Flow cytometric analysis demonstrated clear targeting to the desired cell type allowing simple cell analysis and sorting via FACS.

Flow cytometric analysis of live cells shows clear targeting of the desired cell population. Cells were blocked with for 30 minutes at 4°C using buffers contain 1mg/ml Salmon Sperm DNA and 2% FCS prior to aptamer incubation. Aptamers was incubated with cell lines for 30 minutes at 4°C (35 pmoles per 1×105 cells). The identified Optimer showed no interaction with the negative cell line. Target specific Optimer (green), non-specific aptamer (blue), no aptamer control (red).

Direct ELISA. Indirect ELISA. Sandwich ELISA. Competitive ELISA. Enabling new solutions.

Elisa

Optimer® binders have been successfully developed to a broad range of targets for use in ELISA and ELISA-based platforms.

To ensure optimal function in the ELISA our Optimer discovery processes can be customised to:

  • specific ELISA buffer or matrix requirements
  • allow selectivity between homologous targets for increased accuracy and sensitivity
  • allow cross-reactivity a group of homologous targets for monitoring of whole protein families.

The flexibility of the Optimer platform allows development of Optimer capture or detection reagents, matched Optimer pairs or Optimer-antibody pairs.

Optimer binders can be used as matched pairs for target capture and detection or in conjunction with antibodies to allow the development of sandwich ELISA assays.

Key benefits of Optimer in ELISA

  • Broad target range from small molecules to PTMs and proteins, each tailored to your ELISA buffer and matrix requirements
  • High target specificity and affinity increasing the accuracy of your ELISA
  • Security of supply with consistent batch-to-batch chemical synthesis for reproducible ELISA results
  • Rapid development times mean Optimer binders could be in your hands in just 4 weeks
  • Simple functionalisation for targeted orientation of a capture reagent and flexible detection
  • Improved signal:noise via increased packing density of the capture reagent in the ELISA well plate

Optimer binders for the antibiotic moxifloxacin showed strong dose-dependent signals in ELISA in a variety of complex matrices demonstrating compatibility with numerous clinical, veterinary and environmental assay samples.

Fluorescent ELISA using Optimer specific for moxyfloxacin shows dose-dependent detection of the antibiotic within buffer, 10% human plasma, 10% river water, 10% milk and 10% synthetic urine.

Comparison of an Optimer and commercially available antibody to a serum protein target by ELISA showed an improved dose-dependent signal of the Optimer compared to the antibody over the concentration range.

Biotinylated Optimer binders (1 µM) to a serum protein target showed improved performance compared to a commercially available antibody (100 µM; manufacturer recommended conditions) in an indirect ELISA. Optimer detection was performed using streptavidin-HRP (200 µM). Antibody detection was performed using a secondary antibody conjugated to HRP (200 µM).

Optimer® solutions for novel targets and superior staining

IHC

Optimer binders offer novel solutions for IHC and ICC. From the capability to analyse novel targets to the delivery of robust, reproducible staining, Optimer technology is enabling new and faster solutions for target localisation and spatial mapping.

The detection of Optimer-target interactions can be visualised with fluorescent or chromogenic tags for research and diagnostic use; to identify and validate novel biomarkers, diagnose and prognose disease and monitor therapeutic response.

Key benefits of Optimer for IHC/ICC applications

  • Analyse novel targets or domains with the expanded target range of Optimer
  • Faster staining with the potential for super-resolution imaging due to smaller size of Optimer binders
  • Stable in live cells to enable intracellular target localisation and tracking
  • Reproducible results from standardised and targeted conjugation and batch-to-batch consistency

High-performance, single reagent assays for analyte detection and quantification

Optima beacon

Optimer® beacons are an alternative, fluorescent assay for the detection and quantification of a specific target. Requiring only one reagent for analyte binding and reporting this format offers increased accuracy, consistency and speed of development with lower costs compared to multi-reagent assays.

Utilising FRET-based fluorophores or a compatible fluorophore and quencher, Optimer beacons can yield colour change or gain-of-signal results upon binding the target molecule.

This assay format relies upon the conformational change that occurs when flexible Optimer binders bind to their target analyte. As a result, this format is difficult to develop using traditional, more rigid, affinity ligands, such as antibodies and engineered protein scaffolds.

Optimer beacons can be developed to a range of targets, including small molecules, proteins and cells, for simple solution-based assays that avoid complicated incubations and wash steps.  Just add your sample, mix, and read! These assays are ideal for field-based applications, offering rapid diagnostic solutions with a simple hand-held reader.

Key benefits of Optimer beacons

  • Variety of potential target molecules – from small molecules to proteins and cells
  • Multiplex assays using a variety of fluorophore reporters
  • Rapid development with Optimer binders available in as little as 4 weeks
  • Cost-effective, single-reagent assay format
  • Batch-to-batch consistency and security of supply with simple chemical synthesis and modification

A fluorescent-reporter Optimer beacon was generated for the solution-based detection and quantification of the serine protease thrombin. Upon binding thrombin, a conformational change is induced in the Optimer beacon, resulting in a concentration-dependent fluorescent signal.

The thrombin-specific Optimer beacon shows an increase in signal with an increasing concentration of thrombin protein spiked into the PBS buffer. Low background binding from the BSA negative control demonstrates the specificity of the reagent to the thrombin target.

The sensitivity of a diagnostic test relies on high-performance reagents. Optimer binders are next-generation aptamers that function as ideal affinity reagents for a range of diagnostic tests and assays, including ELISA, lateral flow devices, biosensors, and affinity chromatography.

Aptamer Group offers Optimer-based reagents and services to diagnostic developers to assist in the creation of leading-edge diagnostic tests and assays. Our Optimer technology provides robust antibody alternatives tailored to your specific assay. Optimer binders are ideal for customers who wish to diversify their product portfolio, develop new lines of products, develop diagnostic kits with standardised reagents, extended shelf-life, or remove the need for cold chain supply. The benefits of the Optimer selection process mean that these assays can be made available for targets previously seen as difficult for these assays.

Defined by the nucleic acid sequence and chemically synthesized, Optimer binders offer minimal batch-to-batch consistency, securing the supply chain for the lifecycle of the diagnostic. Optimer reagents offer improved quality, reproducibility and flexibility compared to alternative affinity reagents, to support superior diagnostic assay results.

For special diagnostic applications, our experienced R&D team can work hand-in-hand with you to develop new diagnostic assays and ensure that our next-generation aptamers perform as needed in your real-world application.

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