Clue cells Name given to squamous cells with a large number of Gardnerella vaginalis coccobacilli adherent to the cell surface. Cell outlines and details become blurred. They have been called clue cells. Other bacteria can adhere to cell surface and clue cells are not therefore a reliable diagnostic feature of bacterial vaginosis. The diagnosis of bacterial vaginosis may be proposed only if these cells are observed in a context devoid of inflammatory cells.