Customized Quantitation of Recombinant Therapeutic Proteins using High Precision Streptavidin Biosensors (SAX)

This application note demonstrates the use of bio-layer interferometry (BLI) in the quantitation of five recombinant proteins: insulin, factor VIII, factor IX, erythropoietin (EPO) and granulocyte colony stimulating factor (GCSF). It illustrates the use of BLI in monitoring concentration during protein expression and, thereby, the cell line development for these five proteins. The methods described here can, with proper assay development, also be used for other recombinant proteins. Although only single-analyte step detection is discussed here, a method typically used in higher sample concentrations, this technique can be modified to also amplify signals and increase assay sensitivity for lower concentrations.