Varia9ons in peak area poten9ally result from adsorp9on to the HPLC vial, rather than being method related, which is also supported by the observed run-to-run decrement of the fluorescence response, as depicted in Fig. . AAV6 is shown here as an example, the fluorescence signal can be seen to slightly decrease from run 1 to 2 and from 2 to 3. Moreover, it appears as if the extent of adsorp9on is not the same for full and empty species with the full par9cle peak showing a more pronounced signal loss over 9me.