Figure S1. CD31 staining of endothelial cells (ECs) isolated from mouse lungs cultured in vitro.

Primary ECs were isolated from 1- to 2-wk-old mice using CD31 and ICAM-2 double positive magnetic beads selections and cultured in vitro with EC culturing medium. Then the cells were stained with PE-conjugated CD31 antibody to monitor the purity of the isolated ECs. Almost all the cells were stained positively. Hoechst 33342 was used to show the nuclei. (A, B) Panel (A, B) show the cells of the lung tissues before EC isolation. Only a small portion of the cells were stained by CD31. (C, D) Panel (C, D) show the isolated ECs. Almost all the cells were CD31 positive cells.