DIFFERENTIAL-PULSE POLAROGRAPHY FOR MONITORING CELL-CULTURES

The differential pulse polarography has been used on samples taken fro m the medium during the culture of chinese hamster ovary cells with a view to producing the active principle of an anti-cancer drug. An elec trochemical signal at a potential of -1.8 V with respect to the satura ted calomel electrode was correlated with the lactic acid concentratio n, the pH variation and the number of cells. The peaks observed in oxi dation at potentials -0.35 V and -0.05 V were associated with the tran sformation of the cystine present in the nutrient medium into cysteine and provide an indication of the modification of the reducing power o f the medium during culture. No correlation was found between the elec trochemical behaviour and cell production.