Reduced minus oxidized difference spectrum of flavocytochrome b₅₅₈ samples partially purified from membranes of X-CGD, WT gp91^phox, and ▵488-497 gp91^phox PLB-985 cells. Flavocytochromeb₅₅₈ samples were partially purified from cellular membranes of the indicated cells and dithionite-reduced minus oxidized difference spectrum of the samples were analyzed as described in the Materials and Methods. Results shown are from one representative of triplicate analyses.