SARS-CoV-2 N-protein for use in COVID-19 serological assays (2020-323)

Full length SARS-CoV-2 Nucleocapsid (N) protein expressed by bacteria for use in serological assays to detect previous COVID-19 infection in humans and animals.
Technology No. 2020-323
IP Status: Provisional Patent Application Filed; Application #: 63/018,151


  • Covid-19 serological assays (human and animal)
  • Basic Research
  • Therapeutic development

Key Benefits & Differentiators

  • Highly specific and sensitive performance in assays: A serological study of patients with Covid-19 using N-based ELISA found antibodies in 100% of patients at day 5 post hospitalization. The ELISA test was specific to SARS coronaviruses.
  • Rapid and facile protein production: Protein is inexpensive to produce using fast and accessible bacterial expression systems.
  • Validated in serological assays: Purified N protein used in ELISA to detect antibodies against SARS-CoV-2 in human sera from COVID-19 patients (15+ days from symptom onset) showed high signal.

Facile protein production for COVID-19 serological assays

Serology tests to detect SARS-CoV-2 specific antibodies are needed for clinical/surveillance or epidemiological studies in humans and animals. Drs. Yuying Liang and Hinh Ly’s labs at the University of Minnesota have successfully expressed and purified full-length nucleocapsid (N) protein of the SARS-CoV-2 for use in serological tests. Previous assays developed to identify antibodies to the SARS-CoV-2 Spike (S) protein require a glycolyslated S protein produced in mammalian cells. Such production can be slow, labor intensive and expensive. The spike protein is also highly susceptible to accumulating mutations. However, the N-protein is not glycosylated and can be expressed using bacterial systems that are rapid, robust and easy to work with. Furthermore, results indicate that N-protein may in fact produce more sensitive assays than the S protein.

Phase of Development

TRL: 3-4
Purified N-protein shown to perform in human serological assays to detect previous COVID-19 infection.

Desired Partnerships

This technology is now available for:
  • License
  • Sponsored research
  • Co-development

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