My cell line is having round morphology but i can see some cells in culture which are having different morphology . These spindle shaped cells are not growing fast how can I remove these cells?
You may probably perform clonal selection by serial dilution (until you have theoretically one cell par sample). You then put your samples in 96 wells plates and keep the plates in culture until you get clones (if lucky). You may therefore characterize your clones (according to the line specific properties) to determine whether you obtain homogeneous lines. By such a protocol I obtained several clones of PC 12 . But the grow of the cells at limit dilution is very slow and you probably have to wait for weeks.