Abstract
It was clarified that the reaction velocity at which resazurin (RZ) in RZ test paper changed to resorufin belonged to the firstorder reaction. When RZ test paper containing l0s S.P.C. per ml of fresh milk was cultured at 37°C, the velocity constant was 0.014. It was presumed from these results that the RZ reaction might have been in progress normally in the RZ test paper. Accordingly, this paper was known to be used for a practical test with success.
The reaction velocity of RZ in fresh milk contained to the test paper was almost doubled when there was a rise in temperature by ten degrees centigrade. Incubation of RZ test paper at 18°C for 4.5 hours was to give the same result as that of conventional culture at 37°C for an hour theoretically.
