Supporting Information Flow Induced Dispersion Analysis Rapidly Quantifies Proteins in Human Plasma Samples

In the FIDA experiment, a pressure gradient generates the flow resulting in a parabolic flow profile. The parabolic flow profile inside the capillary distorts the indicator zone resulting in a concentration gradient between the center and the periphery of the capillary (figure S1). Equation 5 in the main manuscript is valid provided there is sufficient time for radial diffusion, and that advective mass transport dominates over diffusive mass transport in the axial direction meaning that the contribution from axial diffusion is insignificant.1 A further prerequisite for applying the theory is that the width of the injected sample zone is sufficiently small compared to the width of the peak when detected.