The cell-free extract of Triton X-114 was subjected to phase separation as such. The culture broth was first supplemented with Triton X-114, well dissolved at 4°C and then warmed up to induce detergent phase separation. Figures 2a and 3a show the distribution of enzyme activity in each phase (detergent-depleted and -rich) for each of the COX sources (cells extract and culture broth) respectively.