©2007 European Journal of Histochemistry

An immunohistochemical differential staining of cancerous cells with anti-cytidine antibody after denaturation of nuclear DNA by acid hydrolysis with 2N HCl at 30°C for 20 min (DNA-instability test) has been used as a marker for malig-nancy. The test was applied to bioptic tissues of human col-orectal polyps assessed histopathologically as hyperplastic polyp (11 cases), tubular adenoma of mild (68 cases), mod-erate (102 cases), and severe (46 cases) dysplasia, and adenocarcinoma (30 cases). The serial sections of the same tissues were also subjected to immunohistochemical stain-ing for Ki67, p53, DNA-fragmentation factor 45 (DFF45) and vascular endothelial growth factor (VEGF). The DNA-instabil-ity test was positive in 30 (100%) adenocarcinoma cases, 46 (100%) severe dysplasia adenoma cases, 36 (35.29%) moderate dysplasia adenoma cases, and 8 (11.76%) mil