CD-MS is a mass spectrometry technique that determines the mass of particles by directly measuring the m/z and charge of ions. CD-MS offers high resolution, high sensitivity, and single-particle analysis capabilities, enabling simultaneous measurement of mass and charge of AAV particles but commercial instruments are not yet widely available. Moreover, CD-MS is able to detect the integrity of packaged AAV genomes directly, which can’t provide by MP.  CD-MS also able to distinguish the small molecular change among the different serotypes.  There is tremendous value in comparing CD-MS and MP, not only for profiling E/P/F capsids but also for correlating low molecular weight and aggregate measurements from
both techniques.