[Method of expansion of late endothelial progenitor cells].

Objective: To validate a novel method of expanding late endothelial progenitor cells (EPC) in vitro.

Methods: We cultured mononuclear cells (MNC) from human peripheral blood on the plate with the feeder layer cells, i.e.

Role of microenvironment in the process of expansion of late endothelial progenitor cell in vitro.

Objective: To study the role of the feeder layer cells as niche in the process of expansion of late endothelial progenitor cell in vitro.

Methods: We cultured mononuclear cells (MNC)from human peripheral blood (PB)on the plate with the feeder layer cells which were irradiated late endothelial progenitor cells(EPC)or human umbilical vein endothelial cells (HUVEC) by EGM-2. After 21 days, the numbers of obtained late EPC colonies were counted separately, and their surface antigen of the late EPC was verified by fluorescence-activated cell sorter (FACS) analysis, and their ability of forming vessel structure with Matrigel in vitro.

[Isolation of single chain antibodies against cell surface molecules by pathfinder selection].

Objective: To isolate single chain antibody fragments (scFv) against cell surface molecules by pathfinder selection from an anti-KG1a cell scFv phage library.

Methods: The anti-KG1a scFv library was enriched by KGla cell panning for three rounds, or unenriched, then processed for pathfinder selection respectively using anti-CD34 monoclonal antibody as pathfinder molecule. ScFv phage clones were randomly picked and identified by binding KG1a cells using immunofluorescein and flow cytometry.