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IITRI now offers an improved efficacy assay for looking at effects of drugs on SARS-CoV-2. Although this assay no longer includes a cytotoxicity readout, we offer a neutral red assay in BSl-2 instead if needed. This current assay uses immunostaining and provides more reliable and consistent data over the previous CPE assay.

This assay looks at the 50% effective concentration (EC50) of the drug against SARS-CoV-2. Briefly, either Vero E6 cells (African green monkey kidney) or Calu-3 (human lung cancer cell) are plated (96 well plate) and allowed to grow to confluency. Serial dilutions of sera are mixed with equal volumes of the virus (typical MOI for SARS-CoV-2 is 0.001-0.01). The virus: sera mixture is added to the cells. The cells are washed and overlaid with EMEM2 with or without the test article.

The test article(s) are serially diluted 3-fold and added to the plate prior to virus inoculation (pretreatment) or after virus inoculation (post treatment).  The last three columns of the plate are used as controls. Forty-eight hours after virus inoculation, cell monolayers are fixed with PFA and incubated with SARS-CoV-2 Anti-NP monoclonal antibody for virus detection.

For more information about this SARS-CoV-2 assays and other studies we currently offer, click here!

SARS-CoV-2 efficacy assay with immunostain


IITRI provides IND-enabling vaccine programs, with over 30 years of experience conducting GLP-compliant toxicology studies. We support vaccine basic research through FDA approval programs for sponsors from government, biotech, academic, and pharma institutions.

Our team would love to speak to anyone looking to test their candidates, contact us.