Relative lactate concentration curves of two colorectal cancer cell lines. Supernatants from the two colorectal cancer cell lines SW480 and SW620. Control specimens were acquired from the supernatants of culture medium only. The concentrations of lactate were examined after incubation for 24 h and 48 h in hypoxia and normoxia conditions. Relative elevated lactate concentrations of SW480 cell lines were 3.24-fold (hypoxia/normoxia: 41.63/12.84; after 24 h incubation) and 3.36-fold (hypoxia/normoxia: 65.70/19.56; after 48 h incubation); however, there were 3.06-fold (hypoxia/normoxia: 30.78/10.05; after 24 h incubation) and 3.17-fold (hypoxia/normoxia: 70.45/22.23; after 48 h incubation) elevated lactate in SW620 cell lines. Values are means ± SD of 3 independent experiments with triplicate dishes.