Physics

Pathology

Cell

Enzyme

Virus

Microtiter plate

Disease

Coronavirus disease 2019 (COVID-19)

High-throughput screening

Infectious disease (medical specialty)

Bioinformatics

Cell culture

Biology

Pandemic

Molecular biology

Virology

Coronavirus

Plate reader

Quantum mechanics

Computational biology

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Genetics

Biochemistry

Medicine

Fluorescence

Antiviral Research

SARS-CoV-2 is a novel pandemic coronavirus that caused a global health and economic crisis. The development of efficient drugs and vaccines against COVID-19 requires detailed knowledge about SARS-CoV-2 biology. Several techniques to detect SARS-CoV-2 infection have been established, mainly based on counting infected cells by staining plaques or foci, or by quantifying the viral genome by PCR. These methods are laborious, time-consuming and expensive and therefore not suitable for a high sample throughput or rapid diagnostics. We here report a novel enzyme-based immunodetection assay that directly quantifies the amount of de novo synthesized viral spike protein within fixed and permeabilized cells. This in-cell ELISA enables a rapid and quantitative detection of SARS-CoV-2 infection in microtiter format, regardless of the virus isolate or target cell culture. It follows the established method of performing ELISA assays and does not require expensive instrumentation. Utilization of the in-cell ELISA allows to e.g. determine TCID50 of virus stocks, antiviral efficiencies (IC50 values) of drugs or neutralizing activity of sera. Thus, the in-cell spike ELISA represents a promising alternative to study SARS-CoV-2 infection and inhibition and may facilitate future research.

An enzyme-based immunodetection assay to quantify SARS-CoV-2 infection