A simple and economical method is described that allows rapid detection of laccase activity in chromatography column fractions during enzyme purification. Aliquots of column eluants are applied to filter paper coated with 2,2＇-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) containing a numbered grid, and incubated at ambient temperature for 20 min. Indications of enzyme activity are simply observed by a colour change. This method avoids having to manually assay each fraction of a chromatographic run for enzyme activity.