We suggest an incubation period of 30 minutes at room temperature. However, depending upon the fixation conditions and the staining system employed, optimal incubation conditions should be determined by the user. Proteolytic enzymatic pretreatment of formalin fixed paraffin embedded tissue sections is recommended prior to immunostaining. Specificity: This antibody reacts with cytokeratins of 58, 56, 52, 60, 51, 48 and 68 kD MW. This antibody is well suited for the staining of a broad spectrum of human keratins. Cellular Localization: Cytoplasmic.