insight evaluation version 3.0 software  (Biacore)

Journal: Nature Communications

Article Title: Omicron SARS-CoV-2 mutations stabilize spike up-RBD conformation and lead to a non-RBM-binding monoclonal antibody escape

doi: 10.1038/s41467-022-32665-7

Figure Lengend Snippet: a , b The S304 antibody was captured on a Protein A chip and then tested for binding with gradient concentrations of the prototypic RBD (3.125 nM, 6.25 nM, 12.5 nM, 25 nM and 50 nM) ( a ) and Omicron RBD (1.5625 nM, 3.125 nM, 6.25 nM, 12.5 nM, and 25 nM) ( b ) in a single-cycle mode. The binding profiles are shown with time (s) on the x -axis and response units (RU) on the y -axis. The black dotted curves were obtained by fitting data to the 1:1 binding model (Biacore Insight Evaluation software v.3.0). K D , k a , and k d values shown are the mean ± standard deviation (SD) of three independent experiments. c VSV-based pseudotyped virus neutralization assay. The prototype and Omicron pseudoviruses were incubated with fourfold serial dilutions of S304 NAb, respectively. The mixture was then added to Vero cells. After 15 h, the infected cells were counted using a CQ1 confocal image cytometer (Yokogawa). Three independent experiments were performed with two replicates. The curves and IC 50 values are one representative data, in which the error bar for each concentration is presented as mean ± SD. Source data are provided as a file.

Article Snippet: The affinity values were calculated using a 1:1 (Langmuir) binding fit model with Biacore Insight Evaluation software v.3.0 (GE Healthcare).

Techniques: Binding Assay, Software, Standard Deviation, Neutralization, Incubation, Infection, Cytometry, Concentration Assay