HEK-293T/ACE2*cl.13 target cells were seeded at 10,000 cells per well in 96-well flat-bottom plates and cultured overnight. The next day, SARS-CoV-2 pseudoviruses (50 ng of p24 worth of pseudovirus) were mixed with serial dilutions of lectins (or buffer control), incubated at 37°C for 30 minutes, and then added to the target cells. At a minimum of 12 hours after infection, the mixture was removed, and the cells were washed with 200 μL of 1x PBS before a media change. On day 4 of the assay, the medium was carefully removed, and the cells were washed twice with 100 μL of 1x PBS and treated with 50 μL of 1x lysis buffer (Promega, Madison, WI). After 3 freeze-thaw cycles, the plates were shaken at 300 rpm at room temperature for 5 minutes. Since the pseudoviruses encode a NanoLuc luciferase gene, the percentage of infection by the pseudoviruses in the inhibitor's presence was measured in a luciferase reporter assay using a 25 μL mix of NanoGlo Substrate and NanoGlo buffer (Promega, Madison, WI) in 1:50 ratio, per manufacturer's directions. Briefly, 25 μL of the lysed cells and 25 μL of the substrate were combined in a white bottom 96 well plate and incubated in the dark for 5 minutes before reading it in a PerkinElmer 1450 Microbeta Liquid Scintillation and Luminescence Counter (Waltham, MA). Non-specific lectin toxicity was not observed with the combination of CV-N and HEK-293T/ACE2*cl.13 target cells in this assay configuration (Supplemental Figure ).