Comparison of the outline of the Schales’ procedure and the developed ChitO-based assay. Schales’ reagent, starting with a yellow color, reacts with the reducing sugars obtained from chitinase activity and after boiling a fading of the yellow color can be monitored at 420 nm. In the ChitO-based assay, the development of the pink product does not require any boiling step and is visible in a short time, depending on the concentration of oligomers in the reaction and the amount of ChitO used. Images edited to improve contrast. ChitO, chito-oligosaccharide oxidase. NAcGlc, N-acetyl-D-glucosamine.