Capillary Isoelectric Focusing — Drift-Diffusion Field Map

This is the 2D field-based counterpart to the 3D particle simulator of the same process. Instead of animating individual protein molecules, it solves the drift-diffusion (Nernst-Planck-style) partial differential equation directly for each species' concentration profile along the capillary, using an explicit finite-volume scheme with no-flux boundaries and mass-conserving upwind advection. Five real proteins spanning pI 1.0 to 10.2 (pepsin, β-lactoglobulin, myoglobin, ribonuclease A and cytochrome c) are shown as a scrolling space-time kymograph — position along the capillary on the horizontal axis, elapsed time scrolling down the vertical axis — so you watch each concentration field sharpen into a steady Gaussian band exactly where the local pH equals that protein's isoelectric point, balanced against thermal diffusion in real time.