Bitsch R, Dersi A, Hötzel D
Klin Wochenschr. 1977 Feb 1;55(3):145-6. doi: 10.1007/BF01490243.
Assaying the activation of pyruvate carboxylase in erythrocytes by measuring the enzyme activity before and after addition of biotin and ATP to the reaction mixture enables to estimate the biotin supply in vitro. According to this method in biotin deficient rats the pyruvate carboxylase-activity increased to 70%, while the increase of activity in supplemented animals amounted to 16%.