Characterization of induced mucosal connective tissue separation - A comparison of six different techniques

Background: Artificial separation of oral mucosa into epithelium and connective tissue represents the first step in investigating both the basement membrane zone and its two components (epithelium and connective tissue) separately. It is a useful tool in analysing the possible role of hepatitis C virus in the pathogenesis of oral lichen planus (OLP). The aim of the present study was to test different methods to separate the epithelium from the connective tissue of oral mucosa affected by OLP as a preliminary step for further immunohistochemical or molecular investigations. Patients and methods: Fourteen tissue biopsies of the oral mucosa of clinically and histopathologically confirmed OLP lesions underwent epithelial connective separation (ECS) using six different reagents. Results and conclusions: Among the separation methods tested, CaCl₂ 1 m at 37°C for 30 min, NaCl 1 m at 4°C for 26 h and elastase at 4°C for 22 h allowed good ECS without structural alteration or tissue loss. The present study provides useful information regarding techniques to separate the epithelium from the connective tissue as a preliminary step to investigate oral mucosa affected by OLP from an immunohistochemical or molecular viewpoint.