Effect of SSCL02446 to SSCL0248 and G-CSF on granulocyte colony formation by rat bone marrow cells. Bone marrow cells were plated in methylcellulose-containing medium supplemented with various concentrations of the small compounds or rhG-CSF, and incubated at 37°C for 8 days. Colonies were observed microscopically, and those containing more than 30 cells were counted (n = 5; mean ± SEM). Thereafter, colonies were recovered from the methylcellulose layer and analyzed by Diff Quik stain.