A modified catalase assay suitable for a plate reader and for the analysis of brain cell cultures.

The enzyme catalase is present in relatively small amounts in neural tissue. A standard spectrophotometric assay for catalase has been modified to make it suitable both for automated assay with a plate reader and for the analysis of neural cell cultures. Catalase activity is determined by measuring residual hydrogen peroxide after incubation with the enzyme. Ferrous ions and thiocyanate are used for the spectrophotometric determination of hydrogen peroxide. The stable visible absorption of ferrithiocyanate can be measured either with a plate reader or a spectrophotometer. The method assays catalase activity from single wells of a tissue culture plate containing 2-3 mg of embryonic rat mesencephalon.