and used as a 'dip stick' method -greatly increasing convenience of this 'hidden' boron catalysis indicator (Figure ). Indicator strips (stained with crystal violet) submerged into a solution of BH3 (2 mM) lost the purple colour giving a white strip within 30 seconds. When no BH3 was present, no colour change of the indicator strip was observed; an indication of 'true' catalysis.