The effects of ammonium and lactate at different concentrations on the growth of 2F7 hybridoma cells, involving glucose consumption, lactate accumulation and cell viability, are investigated. The results suggest that growth inhibition occurs at 2.5 mM ammonium and 2.5 mg/ml lactate, and that severe inhibition occurs at 5 mM ammonium and 5.0 mg/ml lactate.