Table 2.

Analysis of cellular folate pools

5,10-Methylenetetrahydrofolate + tetrahydrofolate (P < 0.001)5-Methyltetrahydrofolate (P < 0.001)10-Formyltetrahydrofolate (P = 0.51)Dihydrofolate + folic acid (P = 0.51)Total folates (P < 0.001)
Wild-type6.7 ± 0.78.5 ± 0.60.9 ± 0.20.8 ± 0.216.8 ± 0.5
PT12.7 ± 0.22.9 ± 0.31.1 ± 0.20.4 ± 0.17.1 ± 0.4
  • NOTE: Wild-type and PT1 cells growing for at least a week in 25 nmol/L 5-CHO-THF were trypsinized, resuspended in ice-cold folate-free RPMI, then washed thrice with ice-cold PBS. The final pellet was analyzed for folate pool distribution as indicated in Materials and Methods. The results are the average + SE of four independent experiments, each conducted in triplicate.