Qualitative assay of exochitinase activity. Row A: Substrate: 4-methylumbelliferyl β-D-N,N'-diacetylchitobioside 2.8 μg total and Row B Substrate: 4-methylumbelliferyl β-D-N,N'-diacetylchitobioside 3.8 μg total. Lane 1. Enzyme: Induced MBP/exochitinase. Lane 2. Enzyme: MBP/exochitinase affinity chromatography fraction. Lane 3. Enzyme: MBP/exochitinase cleavage. Lane 4. Negative control: MBP eluted from ion-exchange chromatography. Lane 5. Enzyme: exochitinase eluted from ion-exchange chromatography after been cleaved from a MBP/exochitinase. Lane 6. Positive control: Enzyme N-acetyl-β-D-glucosaminidase. Lane 7. Substrate alone.