This protocol explains how to use serial dilutions of sample protein to determine the linear ranges of detection for a target and internal loading control, and choose an appropriate amount of sample to load for QWB analysis. Follow the instructions in this section if a housekeeping protein will be used as the internal loading control for QWB normalization. This section also applies to normalization with a pan- specific antibody for analysis of phosphorylation or other post-translational modifications. If you plan to use a total protein stain for normalization, see https://www.protocols.io/view/determining-the-linear-range-for-a-target-protein-g76bzre.