Hydrogen migration is shown as the average peak area ratios, with 50 Th bins, for [c+H]•/[c+2H] (left) and [z+2H]/[z+H]• (right) across all doubly charged fragment ions. EThcD (red triangle), ETcaD (pink cross), AI-ETD (green circle), and ETD without supplemental activation (blue square) are shown for each fragment ion type. Pie charts display the percentage of c-and z•-type isotopic distributions which display hydrogen migration.