Detection of Hæmoglobin, Hæmoglobin–Haptoglobin Complexes and other Substances with Peroxidase Activity after Zone Electrophoresis

Abstract

HÆMOGLOBIN and complexes of serum haptoglobins with hæmoglobin, have peroxidase-like activity which permits their detection in small amounts. For this purpose benzidine^1,2, o-tolidine², guaiacol³ and leucomalachite green⁴ have been employed. However, none of these substances has proved entirely satisfactory. The colours given by benzidine and tolidine fade within minutes⁵, especially when applied to starch-gel strips, and both reagents give appreciable background staining on paper. Instability of benzidine and guaiacol colours used to detect horse-radish peroxidase after paper electrophoresis has been noted also by Jermyn and Thomas⁶, who reported that o-anisidine, p-aminodimethylaniline and hydroquinone were even less satisfactory as reagents for the detection of peroxidases. Malachite green, formed from leucomalachite green, is more stable; but we have found the reagent much less sensitive than either benzidine or tolidine.