Maia et al 2020

Present a strategy that by not requiring isolation of EVs or concentration prior to staining, enables population analysis of EVs in biofluids with unpreceded small volumes.
Conclusion:
Our FC method allows for quality control of isolates of EVs and the study of populations of EVs in samples with small volume available, (e.g. non-lethal longitudinal studies and single-animal collections of mice vitreous humor). By lowering the sample requirement, our FC method multiplies the number of different analytes that can be studied. The molecules of equivalent soluble fluorochrome (MESF) were calculated for PE and CFSE, using SPERO TM Rainbow Beads Calibration Particles (RCP-05-5, Sperotech, USA) and according to the template provided by the manufacture. In summary, the MFI of the beads was measured in the same acquisition settings applied for the EVs samples. The MFI was converted to relative channel number using the formula (Relative Channel# (#CH) = (R/4)log10(MFI), where R is the resolution). Then, the #CH values of the Rainbow beads were plotted against log MESF values and a linear regression was calculated. Using the resulting equation, it was possible to calculate the MESF values for unknown samples.