Blood catalase was purified by CM-cellulose followed by DEAE-cellulose and Sephadex G-150 from blood of Japanese individuals. Rabbit was injected with purified blood catalase emulsified wiwth Freund complete adjuvant. Blood was taken after 6 injections, serum was separated as anti-Japanese blood catalase rabbit serum, and was used for the immunotitration of blood catalase from hypocatalasemic and normal Japanese.
Liver catalase was purified twice from the ammonium sulfate fraction of mice liver supernatant by using the same Sephadex G-200 column. In the same way as for humans, the rabbit was immunized and serum was taken as anti-mice liver catalase tabbit serum, and was used for the immunotitration of blood catalase from acatalasemic, hypocatalasemic and normal mice. Specific activity of catalase in the blood of the hypocatalasemic Japanese was determined by immunotitration. That activity was the same as that of catalase in the blood of normal Japanese individuals. In contrast to this, the specific activity in the blood of hypocatalasemic mice was lower than that of normal mice. Specific activity of residual catalase in the blood of acatalasemic mice showed the lowest value among the activities in the blood of normal, hypocatalasemic and acatalasemic mice.