In addition to the mixed PS particles, a mixed LNP sample (LNP2-mix) was prepared to further test the capability of the system. The adjusted flow sequence proved also successful to separate the two particle populations in the LNP2-mix sample (Figure ). The online approach determined an Rg,avg of 44 and 255 nm for peak 1 and peak 2 of LNP2-mix (automatic fitting), respectively, which agreed reasonably well with an Rg,avg of 47 and 303 nm for LNP2-small and LNP2-large, respectively (Table ). In contrast, offline DLS was not able to differentiate the two populations and instead provided only a single broad and heavily skewed distribution (Figure ). Also here, the automatic and manual fits of the MALLS signals were compared to ensure accurate determination of the LNP particle size. Again, the slopes of the different fitting functions and the resulting Rg values agreed well (Figure and Table ). However, MALLS fitting of the larger particle population (i.e., peak 2) could be done more accurately for LNP2-mix than LNP2-large, as it was not affected by signal clipping due to the upper detector range. Thus, the Rg,avg of peak 2 (255 nm) in LNP2-mix agrees much better with batch DLS (Rh of 230 nm) than LNP2-large (303 nm). For peak 1 and LNP2-small, changes in MALLS fitting did not significantly alter the calculated Rg,avg (44, 46 and 47 nm, respectively). We therefore suspect that the Rh of LNP2-small (74 nm) was instead overestimated by batch DLS.