title: A reliable and reproducible method for the lipase assay in an AOT/isooctane reversed micellar system: modification of the copper-soap colorimetric method.
abstract: The copper-soap method, which is based on the absorbance of a fatty acid-copper complex at 715 nm, is a widely used colorimetric assay to determine the lipase activity in reversed micellar system. However, the absorbance of the bis(2-ethylhexyl) sodium sulfosuccinate (AOT)-copper complex prevents the use of an AOT/isooctane reversed micellar system. An extraction step was added to the original procedure to remove AOT and eliminate interference from the AOT-copper complex. Among the solvents tested, acetonitrile was determined to be the most suitable because it allows for the generation of a reproducible calibration curve with oleic acid that is independent of the AOT concentrations. Based on the validation data, the modified method, which does not experience interference from the AOT-copper complex, could be a useful method with enhanced accuracy and reproducibility for the lipase assay.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Chang Woo
authors.initials: CW
authors.lastname: Kwon
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Park
authors.affiliation: Department of Food Science and Technology, and Department of Interdisciplinary Bio IT Materials, Seoul National University of Science and Technology, Seoul 139-743, Republic of Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea; Center for Food and Bioconvergence, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Republic of Korea. Electronic address: pschang@snu.ac.kr.
authors.forename: Pahn-Shick
authors.initials: PS
authors.lastname: Chang
mesh_terms: D003300:Copper; D008049:Lipase / Q000737:chemistry*; D008823:Micelles; D015203:Reproducibility of Results
chemical_list: D008823:Micelles; D003300:Copper; D008049:Lipase
keywords: Bis(2-ethylhexyl) sodium sulfosuccinate (AOT); Copper-soap colorimetric method; Lipase assay; Reverse micelles