Amicon ultra centrifugal filter cutoff 10 kda

RBD fragment of the Spike protein belonging to SARS-CoV-2 (Raybiotech, Peachtree Corners GA. Cat. 230-30162-1000) was labeled using Alexa Fluor 594 Protein Labeling Kit (ThermoFisher Scientific, Waltham, MA. Cat. A10239) following the manufacturer’s directions. Briefly, 1 mg of protein was dissolved in 0.1 M bicarbonate and then incubated with the Alexa Fluor 594 dye for one hour. The dye was washed using an Amicon-Ultra centrifugal filter cutoff 10 kDa (Merck, Millipore Carrigtwohill, CO. Cat. UFC201024). To assess the efficiency of the label, the protein was measured at 280 nm and 590 nm absorbance using NanoDrop One (ThermoFisher Scientific). There was a ratio of 0.4 mol of dye/mole of protein and a recovery of about 80%.

RBD fragment of the Spike protein belonging to SARS-CoV-2 (Raybiotech, Peachtree Corners GA. Cat. 230-30162-1000) was labeled using Alexa Fluor™ 594 Protein Labeling Kit (ThermoFisher, Waltham, MA. Cat. A10239) following the manufacturer’s directions. Briefly, 1 mg of protein was dissolved in 0.1 M bicarbonate and then incubated with the Alexa Fluor 594 dye for one hour. The dye was washed using an Amicon-Ultra centrifugal filter cutoff 10KDa (Merck, Millipore Carrigtwohill, CO. Cat. UFC201024). To assess the efficiency of the label, the protein was measured at 280 nm and 590 nm absorbance using NanoDrop One (Thermo Scientific). There was a ratio of 0.4 moles of dye/mole of protein and a recovery of about 80%.