fig3

Figure 3. Imaging flow cytometry (IFCM) recovers CD9⁺ objects mainly in one free flow electrophoresis (FEE) fraction. (A) Following optimization, a three-step pH profile (pH 4.5, 4.5, and 7.1) was set up for the fractioning of 3.125 mL of a given MSC-CM. The sample was applied at the vertical position corresponding to that of the collected Fraction 35. The FFE process of continuous zone electrophoresis was performed at 1000 V for 3.5 min in a 3 cm broad separation area. (B) A pherogram of the protein content within the different fractions. (C) The results of IFCM analyses of 25 μL aliquots of obtained fractions that had been stained with anti-CD9 antibodies. The fraction containing detectable CD9⁺ objects (Fraction 9) is labeled by arrows and the black line in (B).