pig and mouse skin extracts supposed to contain the epidermal g2 chalone and mouse liver extracts prepared in a similar way were added to the cell cultures , which were then assayed for mitotic inhibition by means of the colcemid technique , i.e . the number of colcemid-arrested mitoses per 1000 cells during 4 h was counted .
C1518147
arrested mitoses
C0007634
cells