BACKGROUND:Mesenchymal stem cells (MSCs) exist in human tissues.Presently,cell source is single;culture method has great differences;obtained results are not consistent.Thus,it cannot verfy that isolated and cultured cells are identical calls,which is difficult to compare.OBJECTIVE:To compare the biological features of MSCs derived form bone marrow (BM),perpheral blood (PB) and cord blood (CB) under in vitro culture conditions.DESIGN,TIME AND SETTING:The cytological in vitro controlled study was performed at the Department of Hematology,Navy General Hospital of Chinese PLA from June 2007 to December 2008.MATERIALS:A total of 10 donors of hemopoietic stem cell transplantation at the Department of Hematology,Navy General Hospital of Chinese PLA were selected.MB and PB cells were obtained from the same donor,and cell volumes were respectively 20 mL and 2 mL.CB cells (30 mL) were obtained from healthy primipara at the Department of Obstetrics,Navy General Hospital of Chinese PLA.METHODS:MSCs were obtained from BM,PB and CB by Percoll density gradient + adherence method,and then incubated in DMEM/F12 medium containing 10% fetal bovine serum.When 80%-90% confluency,cells were digested in trypsin-EDTA and made into 5×10~8/L cell suspension as P_0.Above-described operation was performed as P_1,and the rest may be deduced by analogy as P_2-P_5.MAIN OUTCOME MEASURES:The following parameters were measured:cell growth morphology;results of Wright-Giemsa staining;results of cytochemistry;cell proliferation amount;cell surface markers using flow cytometry.RESULTS:Time of adherence,time to 50% confluency and time to 80% confluency of BMSCs were earlier comarped with the PBMSCs and UCMSCs.Adherent cells from BM grew in whirpool-like type,while CB and PB did not at 5-7 days.Majority of aderent cells from BM were fibroblast-like cells,and small parts were endothelioid cells.Aderent cells from PB and CB at the fifth generation contained more endothelioid cells and mononuclear and macrophage-like cells besides fibroblast-like cells.PAS stain,Sudan black B stein,alkaline phosphatase (AKP) staining of adherent cells from BM,PB and CB were negative from P_1 to P_5.Compared with P0 cells,number of BMMSCs till P5 was significantly more in PBMSCs and UCMSCs (P ＜ 0.05).Positive rates of CD29,CD44,CD90,CD71,CD105,CD166 and HLA-ABC were 55.9% 92.8% at P0 to P5,but ≤6% following BMMSCs were incubated;19.7%-33.4% at P0 to P5,but ≤10% following PBMSCs were incubated;35.4%-93.2% at P_0 to P_5,but ≤20% following CBMSCs were incubated.Positive rates of CD34,CD45 and HLA-DR were low in BM-,PB-and CB-MSCs.Positive rates of CD14 and CD31 were low in BMMSCs;12.1%-28.3% in PBMSCs,and 8.1%-21.3% in CBMSCs.CONCLUSION:MSCs can be attained from BM,PB and CB.Quantities of MSCs form BM are the highest,with single component,followed by CBMSCs and PBMSCs,with multiple components.