Objective  To cultivate

identify and sort bronchoalveolar stem cells (BASC) derived from normal adult mouse lung.   Methods  After enzymatic digestion of lung tissue with dispase and collagenase in combination

the Sca-1

+

cells were isolated from the obtained pulmonary cells by magnetic cell sorting. These Sca-1

+

cells were cultured in dishes coated with collagen and mo

use fibroblast cell line Swiss-3T3 under a serumfree culture system for BASC

which were identified by the dualcolor immunofluorescent staining clara cell specific antigen (CCA) and surfactant protein C (SP-C). Finally

these pure BASC were isolated by the flow cytometry.   Results  One lung of normal adult mouse could yield (1.6-1.8)×10

7

nucleated cells in this enzyme digestion procedure.  The percentage of Sca-1

+

cells we sorted from lung tissue was much higher than the unsorted [ (87.3±5.9)% and (9.6±1.8)%，P0.05

]

. On the 4th day of culture

the Sca-1

+

cells grew into BASC and other cell colonies. The CD45

-

CD31

-

Sca-1

+

CD34

+

cells accounting for (0.7-1.1)% of the total number of pulmonary cells were isolated by flow cytometry.   Conclusion  Sca-1

+

cells derived from adult mice pulmonary cells can grow into BASC in serumfree culture system

and BASC can be purified by flow cytometry. The established platform provides implications for the research of the lung tumor stem cells from human.