Developing a Serological Test to Detect SARS-CoV-2 Clues
Icahn School of Medicine at Mount Sinai in New York City
There was no shortage of virology projects in Dr. Florian Krammer’s busy laboratory at the Icahn School of Medicine at Mount Sinai in New York City. The team was hard at work developing a universal influenza virus vaccine that could be administered two or three times in a lifetime instead of yearly. They were developing and testing monoclonal antibodies that bind to surface proteins of the influenza virus and other viruses. They were also taking a very close look at an influenza virus surface glycoprotein, called neuraminidase, to improve vaccine effectiveness.
And then, as with so much in life, the Krammer lab changed direction when the COVID-19 pandemic hit.
Dr. Daniel Stadlbauer, a post-doc who oversees and manages the serology core in the Krammer lab says, “When the virus spread was still limited to China, we quickly pivoted to SARS-CoV-2- related research because we thought this might become a global problem, and unfortunately, our foresight was correct.”
He notes that as the virology lab has extensive experience in expressing proteins, they fast-tracked expression of coronavirus surface proteins including the distinctive spike protein. In addition to shipping the plasmids required to express the coronavirus spike protein to over 200 labs across the world, the lab developed a highly specific and sensitive ELISA protocol that leveraged the spike protein and the smaller receptor binding domain to detect SARS-CoV-2 antibodies in human serum.
In the Krammer lab, this ELISA workflow includes use of BioTek’s 405™ LS Microplate Washer and a Synergy™ Hybrid Multi-Mode Reader. “The 405 really increases reproducibility compared to manual washing and opens up time so we can focus on other tasks,” Dr. Stadlbauer remarks. “And the Synergy is the only plate reader that I’ve ever used; it’s intuitive, straightforward, and fast.” He adds that the lab recently obtained a second Synergy reader to keep pace with increased demand, and that they depend on all three BioTek products every day to support their research.
Once fully developed, the ELISA protocol was transferred to the Mount Sinai Laboratory, Center for Clinical Laboratories where it was validated and received emergency use authorization from the U.S. Food & Drug Administration.
With the success of the ELISA, Dr. Stadlbauer notes that the lab published a paper in Nature Medicine, entitled, “A serological assay to detect SARS-CoV-2 seroconversion in humans” and a detailed protocol entitled, “SARS-CoV-2 seroconversion in humans: A detailed protocol for a serological assay, antigen production, and test setup” in Current Protocols in Microbiology so that others could set up the assay in their labs.
The Krammer lab has since resumed their pre-pandemic influenza research and uses the Synergy readers and washer for Promega’s antibody-dependent cellular cytotoxicity (ADCC) assay, neuraminidase inhibition assays, and many other immunoassays. At the same time, they expect to continue working on SARS-CoV-2-related projects for the next few years, including developing a neutralization assay to test if binding antibodies also neutralize the virus and doing live virus challenge studies in small animal models. They are also conducting serosurvey studies, and in fact, findings of one such recent serosurvey were covered in a recent New York Times article, and the full manuscript, “Seroconversion of a city: Longitudinal monitoring of SARS-CoV-2 seroprevalence in New York City” is currently available as an online pre-print.
Note: BioTek, a part of Agilent, did not develop any of the assays stated within this article.
Image 1: Results of the Krammer lab’s serological test, showing various intensities of color indicating the presence of antibodies to the SARS-CoV-2 virus.
Image 2: (L-R) Christina Capuano, Kaijun Jiang, and Daniel Stadlbauer in the Krammer lab’s serology core lab.
To learn more about Icahn School of Medicine at Mount Sinai in New York City., visit their web site.
Thanks to Dr. Florian Krammer at Mount Sinai for sharing his BioTek experience.