Fig. 10. Gel filtration chromatography of endo-β-1,4-glucanases derived from the midgut gland of C. destructor. Samples were loaded onto a Bio-Rad P-100 gel filtration column and the protein concentration (mg protein ml^–1, ) and endo-β-1,4-glucanase activity (µmol reducing sugars produced min^–1 ml^–1, ) measured. (A) Chromatography of combined and concentrated fractions 1–6 from DEAE anion exchange chromatography described in Fig. 5 containing endo-β-1,4-glucanase 1. (B) Size exclusion chromatography of combined and concentrated fractions 16–22 from DEAE chromatography described in Fig. 5 containing endo-β-1,4-glucanase 2.