ENERGY SUPPLY OF THE CELL 



93 



with methylene blue because only half of the dye is 

 reduced. But if the potential goes down to —0.020 

 volts, the culture will be colorless. It would also reduce 



of dye reduceoL 



Fig. 7. — Reduction potentials of different indicators at pH 7.4. 



dichloro-indophenol and naphthol-sulfonate indophenol, 

 but would not change indigo tetra sulfonate nor 

 disulfonate. 



