Multi-wavelength UV-based PAT tool for measuring protein concentration

•A novel PAT tool has been proposed for online dilution free concentration estimation of IgG.•Validated for concentration range 0.8–100 g/L using feature engineering to circumvent saturation at higher concentrations•Application in enabling continuous chromatography/integrated operations demonstrated.•A low-cost, easy to implement tool which uses multi-wavelength UV data•Tested for samples from capture to formulation in a typical downstream train with< 8% variability.