12 wells and well 1 to 8 are positive control well 9 and 10 are control and well 11 and 12 are blank perform serial dilution from well 1 to 8 by transferring 50 u03bcl from well 1 and transfer to well 2 after mixed thoroughly transferring 50 u03bcl from well 2 and transfer to well 3 and so on to well 8 and remove 50 u03bcl from well 8 and the diluted concentrations are 66 6 22 2 7 4 2 47 0 82 0 27 0 091 and 0 03 u03bcm 149 u03bcl nadph cofactor mix and 1 u03bcl 20 mm chinese herbal ingredients or 1 u03bcl 25 w v excipients were added to the well 1 and 2 respectively in a 96 well plate and mixed thoroughly transfer 50 u03bcl from well 1 and 2 and added to well 3 and mixed thoroughly triplicate for each sample the 96 well plate was incubated at 37 u00b0 c for 10 min 100 u03bcl of enzyme substrate mix was added to every well and mixed thoroughly except the blank wells the 96 well plate was incubated at 37 u00b0 c for 40 min 75 u03bcl stop solution was added to every well and mixed thoroughly immediately add 100 u03bcl enzyme substrate mix.