Fig. 4.

Comparison of sulfenic acid levels by protein microarrays from tumor and normal breast tissue lysates. The level of oxidation in each sample expressed as the ratio of sulfenic acid in breast tumor to the patient-matched normal and analyzed according to age (A) or histological grade (B). A ratio greater than one indicates that thiol oxidation is elevated in malignant tissue, relative to the paired sample. Chemifluorescence intensity of microarray spots is indicated with bars. The standard deviation for three replicate spots was less than ± 15%.