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Neutralizing Antibody (NAb) & Total Antibody (TAb) Assays

Precision is a global leader in the development and validation of neutralizing antibody (NAb) and total antibody (TAb) assays

Precision has extensive experience in developing neutralizing antibody and total antibody assays to measure pre-existing antibodies to gene therapy viral vector-based therapeutics across multiple types of vectors and capsid types, and can support development of gene therapy NAb/TAb assays into commercial CDx

AAV experience table

Expertise in NAb/TAb assays for gene therapy

Precision scientific team has developed and validated both NAb and TAb assays in both humans and NHP for several capsid types.

In addition, Precision has run >8,000 samples on GxP-validated assays and continues to support the most prominent companies developing gene therapies.

Case Study

Development of a NAb CDx for a gene therapy


Because preexisting antibodies may hamper transduction efficiency and reduce efficacy of AAV5 vector-based therapy, the sponsor wanted us to develop and validate an AAV5 NAb CDx to identify patients most likely to benefit from treatment.


We developed and optimized a cell-based luciferase reporter assay that could detect and measure anti-AAV5 capsid antibodies capable of neutralizing viral transduction of HEK 293 cells. This project included maintenance of the cell bank, running the assay, and testing clinical samples.

We are also developing a single-site CDx using our ISO 13485-certified and FDA 21 CFR 820-compliant laboratory facilities. As of early 2019, this project included full regulatory, biostatistical, and commercial services for the CDx, including both strategic and tactical support for all activities throughout the product life cycle.

text and media CDx commercialisation

Regulatory solutions for NAb/TAb CDx

Precision also support development and commercialization of total antibody and neutralizing antibody companion diagnostics, including:

  • FDA diagnostic pre-submission and modular PMA submissions
  • Complete LDT analytical studies under full design control

Our experience speaks for itself-we’ve already successfully completed over 100 CDx regulatory filings globally

Explore CDx Regulatory Services

Related Services

  • Large Molecule PK

    Development, validation, and implementation using ELISAs and MSD assays for biologics, flow cytometry and ddPCR for cell-based therapies, and Quanterix SIMOA® for ultrasensitive analyte detection
  • Cytokine

    MesoScale Discovery (MSD)

    Measuring a range of analytes in complex sample matrices consistently and at high sensitivity, with applications including ADA, NAb, TAb, and PK assays

    Services using the gold standard for quantitative antibody-based bioanalysis, with specialization in immunogenicity assay development