Laccase (EC1.10.3.2) is a polyphenol oxidase containing copper. It belongs to the ceruloplasmic oxidase
family. Laccase is a kind of environmental protection enzyme which exists in mushroom, fungus and plant.
Its unique catalytic properties are widely used in biological detection.
Laccase can decompose substrate ABTS to produce ABTS free radicals. Its absorption coefficient at
420nm is much higher than that of ABTS. Laccase activity can be calculated by measuring the increasing
rate of ABTS radicals.
Required but Not Provided:
Spectrophotometer, balance, low temperature desk centrifuge, transferpettor, oscillating instrument, 1 mL
glass cuvette, mortar/ homogenizer, water bath, ice and distilled water.
Protocol
I. Preparation:
(1) Tissue: according to the ratio of mass (g): extraction volume (mL): 1:5-10 to add the extract reagent. It
is suggested that add 1 mL of extract to 0.1 g of tissue. Homogenate on ice. Centrifuge at 10000 g 4℃ for
10 min. Take the supernatant on ice for test.
(2) Cells: according to the number of the cells (104): the volume of the extract (mL) is 500~1000:1. It is
suggested that add 1 mL of extraction reagent to 500 million of cells. Breaking cells by ultrasonic wave in
