Cellulase assays

Cellulase assays

Cellulase enzymes show activity during the ripening of some fruits, where their effects on cell walls results in softening of the fruit. In cases of programmed cell death, such as the formation of aerenchyma (large air spaces in the cortex of plants in flooded soils), and in the abscission zones of leaves and fruits, cellulases are once again very active, breaking down the cellulose walls of the dead cells. Two possible protocols are described here, a gel diffusion assay method and a viscosity reduction assay method.

Gel diffusion method

• Prepare an agar gel containing 1.7% agar and 0.5% CMC (carboxymethylcellulose). Pour this gel into petri dishes and allow it to set.
  
  

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  Viscosity reduction method

  The technique is based on the action of cellulase enzymes which shorten the lengths of cellulose molecules in a viscous solution of wallpaper paste and cause it to become less viscous (runnier).

  • Make up a 2% (w/v) wallpaper paste solution, sufficient to provide 25 cm³ for each sample to be tested.