The use of X-ray microanalysis to investigate problems encountered in enzyme cytochemistry


  • This research was supported by the Scientific Research Council. Grant No. B/RG/00869.


The nature of the reaction product and non-specific staining obtained using lead salt methods, for localizing phosphatase activities, has been determined using energy dispersive X-ray microanalysis. The detectability of ‘non-electron dense’ elements has permitted the development of an alternative azo dye method involving the coupling of an enzymatically released, insoluble primary reaction product with the active diazotate of 2, 5-dichloroaniline (Fast Scarlet GG). The resultant azo dye was detected in ultrathin cryosections. The localization achieved by this method and the advantages of combining ultracryotomy and X-ray microanalysis with enzyme cytochemistry is discussed.