title: A simple assay for measuring catalase activity: a visual approach.
abstract: In this study, an assay that combines the ease and simplicity of the qualitative approach for measuring catalase activity was developed. The assay reagents comprised only hydrogen peroxide and Triton X-100. The enzyme-generated oxygen bubbles trapped by Triton X-100 were visualized as foam, whose height was estimated. A calibration plot using the defined unit of catalase activity yielded the best linear fit over a range of 20-300 units (U) (y = 0.3794x - 2.0909, r(2) = 0.993). The assay precision and reproducibility at 100 U were 4.6% and 4.8%, respectively. The applicability of the assay for measuring the catalase activity of various samples was assessed using laboratory strains of Escherichia coli, catalase-deficient isogenic mutants, clinically isolated Shiga toxin-producing E. coli, and human cells. The assay generated reproducible results. In conclusion, this new assay can be used to measure the catalase activity of bacterial isolates and human cells.
authors.affiliation: Department of Bacteriology, The Jikei University School of Medicine.
authors.forename: Tadayuki
authors.initials: T
authors.lastname: Iwase
authors.forename: Akiko
authors.initials: A
authors.lastname: Tajima
authors.forename: Shinya
authors.initials: S
authors.lastname: Sugimoto
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Okuda
authors.forename: Ippei
authors.initials: I
authors.lastname: Hironaka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kamata
authors.forename: Koji
authors.initials: K
authors.lastname: Takada
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Mizunoe
mesh_terms: D002374:Catalase / Q000378:metabolism*; D002460:Cell Line; D004789:Enzyme Activation; D057075:Enzyme Assays / Q000379:methods*; D006801:Humans
chemical_list: D002374:Catalase