The protease solution contained 1 mL of stock protease in 19 mL of borax−NaOH buffer of the same pH as used for the wash buffer. The incubation time at 30 °C, or the immobilization period, varied in different experiments.
The beads were then stored at 4 °C for 18 h while still in the protease solution. Before use, the immobilized enzyme beads
were thoroughly washed first with a 2 M solution of NaCl and then with deionized water.