EVerZom provides exosome dosage services to quantify proteins, nucleic acids and lipids.
Qubit Fluorometric Quantification
Micro BCA & Bradford assays
Proteins are both a major component and a contaminant of EV preparations. Different protein assays can be used to quantify the total protein content. Bradford assay is based on complexation of aromatic amino acids with Coomassie blue, inducing a color shift followed by spectroscopy. Its limit of protein quantification is from 5 µg/mL to 120 µg/mL. To increase sensitivity, the micro BCA (bicinchoninic acid) assays consists to follow the amine-dependent reduction of Cu(II) in Cu(I). Typically, it permits to quantify proteins from 0.5 µg/mL. However, it is more sensitive to contaminants, such as free amino acids from the culture medium. Both BCA and bradford require a sample volume of 100 µL.