Differential staining of dysplastic aberrant crypt foci in the colon facilitates prediction of carcinogenic potentials of chemicals in rats

Cancer Lett. 2005 Mar 18;220(1):67-74. doi: 10.1016/j.canlet.2004.10.026.


We developed a novel and simple method to identify dysplastic aberrant crypt foci (ACF) induced in rats by colon carcinogens more efficiently and selectively without conducting laborious histological examination, which usually requires enough time to get final diagnosis. By adding a simple decolorization process with 70% methanol after conventional 0.2% methylene blue staining, dysplastic ACF could be differentially contrasted. To examine the validity of this novel method, which we refer to as differential staining, we analyzed colonic lesions induced by three heterocyclic amines, including 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, and found that the number of dysplastic ACF detected more precisely reflected their carcinogenic potential than the total numbers of ACF.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Animals
  • Carcinogenicity Tests / methods*
  • Carcinogens
  • Colonic Neoplasms / chemically induced*
  • Imidazoles
  • Male
  • Methylene Blue
  • Precancerous Conditions / chemically induced*
  • Precancerous Conditions / diagnosis
  • Rats
  • Rats, Inbred F344
  • Staining and Labeling*


  • Carcinogens
  • Imidazoles
  • 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine
  • Methylene Blue