Contract and Custom Services
With decades of experience in the field of recombinant protein production and assay development, The Native Antigen Company is able to undertake a range of custom projects on your behalf.
Honesty and transparency is central to what we do. Nothing hampers collaboration more than poor communication, so we have established systems to ensure that our clients are fully informed of their project’s progress. During a project you will have direct access to the R&D team, who provide regular updates on progress.
Our molecular biologists use a range of bioinformatics tools to design constructs specific to your protein, system and application. Different strategies and approaches are considered, including, but not limited to: expression host, purification tags, signal peptide sequences, domain boundaries and mutagenesis. Once designed, genes are synthesised and cloned into a suitable vector and sequence-verified upon completion. Work with our highly experienced team to leverage:
‣ A collaborative approach using different sequence optimisation and cloning strategies
‣ Construct design experience in a wide range of protein classes and applications
‣ Custom in-house vectors for E. coli, insect and mammalian expression
‣ A variety of tags for improving solubility, secretion, yield and purity
‣ Parallelisation using multiple constructs and expression systems to maximise success
‣ Bulk plasmid preparation (Gigaprep) up to 100mg of DNA
Whether you need a human biomarker, membrane protein or functional enzyme, we’re able to develop, produce and scale-manufacture your protein of interest. As part of our recombinant protein expression services, we offer:
‣ Parellelisation of multiple constructs across different hosts
‣ Expression in a range of host expression systems, including mammalian, insect and E. coli
‣ Small-scale testing and expression optimisation (go/no-go decision stages)
‣ Scalability in adherent and suspension cultures
‣ Bespoke and modular workflows
‣ Membrane, cytoplasm and secretion-specific expression
In addition to recombinant expression, our microbiology team can produce native antigens and toxins in the form of whole bacterial cells, bacterial lysates and viral lysates, with options for further downstream purification. We operate to BSL-2 standards and offer multiple validated options for inactivating bacteria, viruses and toxins.
We offer a broad range of purification methods to achieve maximal purity and batch-consistency. Purifying your protein of interest will begin with a discussion about your specific requirements, which may include functional protein purity, enzymatic activity, removal of specific contaminants, or the use of bespoke buffers. Following consultation, we can work with you to develop a custom strategy for purification. Typical steps in purification workflow may include:
‣ Cell disruption or concentration of secreted protein by TFF
‣ Column purification (affinity, ion exchange, hydrophobic interaction, size exclusion)
‣ QC by SDS-PAGE, Western blot and ELISA
With additional purification techniques including:
‣ Protein refolding screen and scale-up by dilution/dialysis
‣ Membrane preparation by ultra-centrifugation
‣ Endotoxin removal
‣ In vitro protein modification
If required, more extensive QC can also be carried out, including, but not limited to, mass spectroscopy, circular dichroism, confocal microscopy, electron microscopy, analytical ultracentrifugation and N-terminal sequencing.
Utilise our expertise in antibody generation to develop high-quality, target-specific polyclonal, monoclonal and recombinant antibodies. Following a consultation with one of our experts, we can decide on the process that gives you the best chance of raising an antibody for its desired specifications. After successful completion, we also offer a range of additional services, including storage of bulk antibody, hybridoma banking, bulk antibody production, conjugation, and a range of antibody engineering options including chimerisation.
Our antibody generation services include:
‣ Highly purified monoclonal, polyclonal and recombinant antibodies
‣ Protein G/A and antigen affinity purification
‣ Complete and transparent datasets
‣ Up to 100g quantities
Our assay team has decades of experience in developing both de novo ELISAs and partnering with our clients to support their assay optimisation and validation. Not only do customer benefit from the consultancy with our senior assay development scientists, but our in house expression systems can also be used to produce natively-folded and fully glycosylated proteins and antibodies, giving your ELISA the edge against the competition.
Depending on the application, we can develop and advise on a range of formats, from direct antigen-down ELISAs to more complex double antigen binding (DABA) assays or those that rely on competitive binding. In addition to ELISA development, we provide a range of bespoke services that offer the flexibility to assess the best antibody pairs, through to the development of an IVD-marked kit.
Our ELISA development capabilities include:
‣ ELISA design and format consultancy
‣ Extensive optimisation and validation
‣ Custom antigen and antibody production
‣ Raising antibodies with custom antigens
‣ Antigen-antibody pair optimisation
‣ Conjugation
The Native Antigen Company now offers a range of services for virology research and the development of diagnostics, therapeutics, and vaccines. We provide a flexible and customised approach to each study, which is carefully discussed with the client to provide the most informative outcome.
Plaque, Immunofocus and TCID50 Assays
Plaque assays, immunofocus assays and TCID50 assays are used to determine the number of infectious particles in a sample. Starting with a monolayer of permissive cells, virus is added at serial dilutions and incubated until plaques, foci, or cell death become visible. Infectious virus titre is determined by counting plaques or foci for plaque assays and immunofocus assays, or by determining the virus dilution at which 50% of wells are infected.
Our plaque assay offering includes the following:
+ Quantification of infectious units in cell culture media or tissue samples
+ Study of virus release in mode-of-action studies
+ Determination of particle per infectious unit (particle:pfu) in combination with qRT-PCR
We offer infectious units quantification for the following viruses:
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Microneutralisation Assays
Microneutralisation assays are used to determine the neutralising properties of serum or antibodies against a virus of interest. The assay involves incubation of an optimised amount of virus with a serial dilution of antibody or serum, followed by infection of a cell monolayer. Percentage of infection are determined by quantifying the number of cells expressing virus antigen, detected by immunofluorescence staining.
Our neutralisation assay offering includes the following:
+ Quantification of neutralising titres for serum, antibody, and hybridoma samples using immunofluorescence staining
+ Quantification of antiviral activity of compounds or biomolecules inhibiting viral entry
+ Internal controls using known concentrations of neutralising and isotype antibodies, as well as untreated and uninfected controls
We offer microneutralisation assays for the following viruses:
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Antibody-Dependent Enhancement Assays
Antibody-dependent enhancement (ADE) is a phenomenon by which non-neutralising antibodies bind to a virus and are then internalised by cells carrying the Fc Receptor, causing concomitant internalisation of the bound virus. If these cells (typically macrophages) are permissive to viral replication, the antibodies enhance infection via this pathway. ADE assays rely on pre-incubation of a serial dilution of antibody with a fixed concentration of virus, which is then added to cells carrying Fc receptors. ADE is measured by comparing the percentage of infected cells at different serum concentrations with untreated/non-enhancing controls.
Our ADE assay offering includes the following:
+ Quantification of enhancing titres for serum and antibodies using Immunostaining
+ Internal controls using known concentrations of enhancing and isotype antibodies, as well as untreated and uninfected controls
We offer ADE assays for the following viruses:
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Antiviral Drug Screening
Antiviral testing is performed to reveal the antiviral properties of compounds, small molecules, or biologicals. Test articles can be tested at a single concentration or at multiple concentrations, and the compounds can be introduced at different stages of infection.
Our antiviral drug screening offering includes the following:
+ CPE assays
+ Immunofluorescence assays with single or multiple rounds of infection
+ High content imaging
+ High-throughput screening
+ EC50 and TC50 determination
+ Cytotoxicity testing over the same range of concentrations
We offer antiviral drug testing assays for the following viruses:
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