p53 is the most frequently altered tumor-suppressor gene in
skin cancer. In normal tissues the p53
protein (wild type) has a very short half-life and it is not detectable immunohistochemically. In contrast, the mutant p53
protein has an extended half-life in
tumor cells and can be detected by immunohistochemical methods. p53 is widely used as an
indicator of
tumor aggression and progression. Fixation methods especially
formaldehyde based fixation may mask the immunohistochemical detection of p53
protein but
antigen retrieval methods enhance the inmmunohistochemical detection of p53
protein by remodification of
protein structure. This study was designed to evaluate the efficacy of different
fixatives, of microwaving and microwave pretreatment method to retrieve p53 immunoreactivity in
paraffin-embedded non-lesioned (adjacent normal tissue) human skin samples or pathological human skin samples diagnosed as
basal cell carcinoma. The samples were fixed at RT and/or in microwave oven either in neutral buffered
formalin or alcohol for different time periods. For
antigen retrieval, the sections were irradiated in a microwave oven for 5 cycles in 10 mM
citrate buffer (pH 6.00). In this study the effects of six different fixation methods on the immunohistochemical staining have been investigated in basal cell
tumor specimens. The application of
antigen retrieval method was also examined and compared. Optimal results were obtained using samples fixed in alcohol either at room temperature (24 h) or in microwave oven.