Localization of acid phosphatase activity in Giardia lamblia and Giardia muris trophozoites

J Protozool. 1987 Feb;34(1):80-3. doi: 10.1111/j.1550-7408.1987.tb03137.x.


Numerous membrane-bounded vacuoles are found adjacent to the plasma membrane of the pathogenic protozoan Giardia lamblia. The function of these vacuoles has been discussed by several authors. Approximately 100-400 nm in diameter with a core of low electron density, they have been suggested to be mitochondria, mucocysts, lysosomes, and endocytotic vacuoles. Enzyme cytochemical localization for acid phosphatase activity using cerium as a capturing agent demonstrates reaction product in these vacuoles as well as in the endoplasmic reticulum and nuclear envelope cisternae. The distribution of reaction product suggests the vacuoles are lysosome-like; however, their function and development remain in question.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acid Phosphatase / analysis*
  • Animals
  • Electrophoresis, Polyacrylamide Gel
  • Giardia / analysis
  • Giardia / enzymology*
  • Giardia / ultrastructure
  • Histocytochemistry
  • Microscopy, Electron
  • Vacuoles / enzymology


  • Acid Phosphatase