OBJECTIVETo develop an effective method for isolating and culturing single cancer stem cells.

METHODSThe capillary glass tube was stretched on fire and connected to a sterile plastic tube to prepare the single cell separation apparatus. Single SW480 cell clone spheres in serum-free culture were marked with CD133 and CK7, and the single cancer stem cells were separated and cultivated in 96-well plates or microdrop covered by paraffin.

RESULTSSW480 cell clone formation rate was about 1.04%, and the cell clone spheres highly expressed CD133 with low CK7 expression. The isolation of the single cancer stem cells showed a success rate of 98.99% using the separation device. The cell division profile was comparable between the cell cultures in microdrop and 96-well plates in the initial 2 cell divisions (P>0.05), whereas prolonged cell division occurred afterwards in the microdrop culture as compared to 96-well plate culture. The cell population expansion of the single cancer stem cells was similar between microdrop culture (11.5%, 22/192) and 96-well plate culture (9.2%, 17/184) (P>0.05).

CONCLUSIONSSingle SW480 cells can develop into cancer stem cell spheres. Microdrop culture is convenient and stable, and can be the primary choice for single cancer stem cell culture.