Figure 3.

Comparison of ETD versis CID. Fragment maps of H4_S1acK5acK8acK12acK16acK20me2 from CID (a) and ETD (b) for the parent ion with m/z = 820.61 (z = 16) eluting at 60.88 min are shown. CID, collision induced dissociation ETD, electron transfer dissociation.