Internal medicine

Disease

Coronavirus disease 2019 (COVID-19)

Infectious disease (medical specialty)

Pandemic

Outbreak

Antibody

Virology

Emergency medicine

Chemistry

Immunology

Blood collection

2019-20 coronavirus outbreak

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

Dried blood

Chromatography

Medicine

Proceedings of the National Academy of Sciences

Significance COVID-19, caused by SARS-CoV-2, led to an unprecedented global health crisis. As the majority of people infected with SARS-CoV-2 have no or only mild symptoms, many cases aren’t captured by direct testing. However, it is important to establish the true spread of the virus by identifying how many people have been exposed. Detection of anti–SARS-CoV-2–specific antibodies in blood samples can help us understand how the pandemic is evolving over time. We developed a sensitive and specific assay that performs 1,024 measurements in parallel. To enable decentralized blood sample collection, the method can detect antibodies in a small drop of blood obtainable by finger pricking, and the blood can be collected and shipped with a simple, low-cost blood glucose test strip.

A high-throughput microfluidic nanoimmunoassay for detecting anti–SARS-CoV-2 antibodies in serum or ultralow-volume blood samples