COVID-19 spike protein interaction studies commence at Fluidic Analytics

Published on March 27th, 2020

Whilst most of us remain indoors to do our part to slow the spread of COVID-19 caused by the SARS‑CoV‑2 virus, scientists at Fluidic Analytics have remained committed to doing their part to analyzing the virus’ interactions with antibodies.

Specifically, the team have rigorously been exploring the use of microfluidic diffusional sizing (MDS) technology to characterize the interactions of SARS‑CoV‑2 with antibodies, in order to reveal the binding affinity of these interactions.

The team have now completed important benchmark studies in showing how the viral spike protein binds to an anti‑SARS‑CoV spike antibody. This initial experiment was performed in PBS buffer and will serve as a vital control study for the upcoming characterization of the interaction in blood serum. The ability to measure antibody–virus binding affinity in solution and directly in blood serum paves the way for subsequent analysis of individual patient-immune response to infection with SARS‑CoV‑2, or indeed any other virus of interest.

Whilst the application note is yet to be published, binding-affinity data has been released by Fluidic Analytics:

Figure 1: The binding curve of SARS‑CoV‑2 spike S1 domain against anti-SARS mAb gave an affinity of 100 nM. The hydrodynamic radius (Rh) of free S1 and in complex with anti-SARS mAb were 4.1 nm and 6.1 nm respectively, consistent with a 1:1 binding ratio between the spike protein and the antibody.


For more information on Fluidic Analytics COVID-19 spike protein interaction studies, please email: