Table 1.

The most commonly used nomenclature, isolation method, and associated identification markers of endothelial progenitor cells (EPCs) in vitro.

Cell culture models
Name	Other names	Isolation method	Identifying markers	Reference
Endothelial colony-forming cells	Blood outgrowth endothelial cells Late outgrowth EPCs	Peripheral blood mononuclear cells (PBMNCs) are isolated from peripheral blood with a Ficoll gradient. Cells are plated on collagen-1, grown in cEGM-2, and colonies appear between 14 and 21 days in culture	Expression of CD31; CD141; CD105; CD146; CD144; vWF; Flk-1; CD34; CD133; CD117; eNOS	(12, 18)
			Negative staining for CD45, CD14
			Single-cell assay: able to repopulate from a single cell
			Able to form capillary structures in vitro
			Cobblestone morphology
Colony-forming unit-endothelial cells	Early outgrowth EPCs, CFU-Hill EPCs	PBMNCs are isolated from peripheral blood similar to above, plated on fibronectin, grown in M199 medium, and colonies appear between 5 and 7 days in culture	Expression of CD34, vWF, CD144, Flk-1, UEA-1, Tie-2	(10, 14, 19)
			DiI-Ac-LDL uptake
			Negative staining for VCAM-1
			Spindle-like morphology

vWF, von Willebrand factor; Flk-1, vascular endothelial growth factor receptor-2; eNOS, endothelial nitric oxide synthase; UEA-1, Ulex europaeus agglutinin-1; VCAM-1, vascular cell adhesion molecule-1; Tie-2, TEK receptor tyrosine kinase; DiI-Ac-LDL, DiI-conjugated acetylated low-density lipoprotein.