[Comparative studies on the time course of proliferating cell nuclear antigen and bromodeoxyuridine staining pattern...

Immunohistochemical staining pattern of proliferating cell nuclear antigen (PCNA) was examined in regenerating rat liver specimens fixed under the various conditions (10% buffered formalin for 6hr, 1% paraformaldehyde for 6hr, 100% methanol for 4hr, 70% ethanol for 6hr). Time course of PCNA staining pattern after hepatectomy in the specimens fixed with 100% methanol or 70% ethanol coincided closely with that of bromodeoxyuridine (BrdU) staining pattern, which is known to be standard marker of cell proliferation. Similar result was obtained in fixation with 10% buffered formalin (10% BF) or 1% paraformaldehyde (1% PFA) when only granular staining pattern of PCNA was evaluated. These findings suggest that granular immunostaining of PCNA in tissue specimens fixed with 100% methanol, 70% ethanol, 10% BF or 1% PFA is useful for evaluating the extent of cell proliferation.