because we did not obtain pure s or g2/m populations by elutriation or by harvesting synchronized cells , a mathematical procedure -- which assumed that the measured polyamine levels for any population were linearly related to the fraction of cells in the g1 , s , and g2/m phases times the polyamine levels in these phases and that polyamine levels did not vary within these phases -- was used to estimate 'true ' phase-specific polyamine levels ( levels to be expected if perfect synchrony were achieved ) .
C0007634
cells
C0079396
g2