Single molecule assays were performed on bovine intestinal alkaline phosphatase and the recombinant enzyme expressed in Pichia pastoris using a capillary electrophoresis-based method. The catalytic rates for the bovine and recombinant enzymes were found to be 11,000 +/- 7000 min(-1) (N = 161) and 12,000 +/- 7000 min(-1) (N = 173), respectively. Mean catalytic rates and variances did not differ significantly between the enzyme from both sources. Furthermore, the distribution of catalytic rates were indistinguishable. (C) 2015 Elsevier Inc. All rights reserved.