if one of these two processes is slower than the normal respiration , the dye can not increase the rate of oxygen consumption ( phenol indophenol at low concentrations which is kept reduced by the cell is very slowly reoxidized by atmospheric oxygen , on the other hand safranin and neutral red which are not reduced by the cell or at least too slowly reduced , though rapidly reoxidized by air ) .
C0031428
phenol
C0021250
indophenol