Figure 5

Binding of FITC-conjugated X-2 to birch pulp. Control staining of fibres with FITC-conjugated G-4 is shown in A (unbleached birch pulp) and B (unbleached birch pulp, after hemicelluloses removal). Binding of X-2 to unbleached pulp fibres was mostly observed at the sites of fibre damage (C), whereas bleached birch pulp were more uniformly stained (E) like the wood sections in Figure 4. Removal of hemicelluloses from both pulp types reduced the fluorescent signal (D, F) proving the specificity of X-2 for xylan. It was possible to treat pulps until complete removal of xylan recognised by X-2 was obtained. Scale bars = 100 mm for A – D, 200 mm for E, F.