Enzyme affinity towards pretreated samples. CLSM images of lab-scale pretreated wheat leaves (1, 2), stems (3, 4) and industrially pretreated wheat straw (5, 6) incubated with a fluorescently labelled endoglucanase (1, 3, 5) or exoglucanase (2, 4, 6) showing the level of adhesion to fiber (A), epidermal (B) and parenchyma (C) cells. In order to facilitate comparison, all images were taken with the same objective (10x) and setting of laser intensity (20%) and gain (500 V). Blue indicates off-scale high adhesion. Images were taken at the level where the emission intensity was highest for the cell type of interest. Note the high affinity to epidermal cells compared to fibers and parenchyma cells after pretreatment.