Transient Antibody Expression Platform Drives Batch-to-Batch Reproducibility for COVID-19 Diagnostic Assay

Transient recombinant antibody expression enables the quick and affordable production of sequence-defined antibodies with the highest possible batch-to-batch reproducibility, permitting scale up to gram quantity production without the time-consuming need to generate a stable cell line. Reagent reproducibility is particularly important for the development of diagnostic tests, as IVD manufacturers must demonstrate that an assay will perform exactly as intended for the entire lifespan of a diagnostic.

In a new application note, we looked at the batch-to-batch reproducibility of our anti-coronavirus spike glycoprotein antibody CR3022, which has been shown to detect SARS-CoV-2 and used in COVID-19 diagnostic assays since the onset of the pandemic. We sought to determine if there were any significant differences in signals between three lots and three isotypes of our recombinant CR3022 antibody when run on an external COVID-19 antibody test. To manufacture the CR3022 antibodies, we used our HEXpress™ antibody expression platform, which enables serum-free mammalian transient expression to produce recombinant antibodies at milligram-to-gram scales. Three different isotypes of the same antibody clone (IgM, IgG1 and IgG3) were manufactured on different days in three lots.

Batch-to-batch reproducibility and stability of the recombinant protein were confirmed, with data showing minimal variability between lots in response to increasing concentration and measuring signal output. The results indicate a reproducible manufacturing process for the recombinant antibodies, meaning they can be used interchangeably to calibrate or evaluate the performance of a serology test for anti-SARS-CoV-2 antibodies.

Lot-to-lot comparison data for the recombinant human anti-coronavirus antibody in IgG1 isotype is above. For the full data set and methods, download the application note using the form below.