Best Antibody Pairs for LFA Assays

While traditional PCR-based assay remains as the golden standard for COVID-diagnosis, there is an increasing demand in other methods that enable quicker, easier, and more cost-effective tests. Lateral flow immunoassay (LFA) is an alternative platform that can be used to detect viral antigens in biological samples. Such tests rely on the availability of antibody pairs that can recognize the target antigen with desired specificity and sensitivity. Hundreds of antibodies against N and S proteins have been made available in recent months. Screening this large resource for a suitable pair has become a major speed limiting factor.

In a recent study supported by The Global Good Fund and Global Health Labs (created by Gates Ventures and the Gates Foundation), authors from Global Health Labs, Intellectual Ventures Laboratory, and PATH systematically evaluated all commercially available antibodies using a high throughput screening process directly on nitrocellulose. The study identified a dozen pairs with the best potential to deliver optimal results in LFA assays.

Table: Antibody pairs selected to be screened against clinical samples are ranked according to average performance by S-N and S/N in the clinical screen. Average rank from all four robot screening rounds are also shown.
Ref: David Cate, et al., Antibody Screening Results for Anti-Nucleocapsid Antibodies Towards the Development of a SARS-CoV-2 Nucleocapsid Protein Antigen Detecting Lateral Flow Assay. ChemRxiv.2020