PETRI DISH HAVING IMPROVED MEANS FOR RELEASABLY HOLDING THE COVER TO THE BASE BY FRICTION FITTING

摘要

A contact plate for growing cell cultures, bacteria cultures, and the like, comprising a base and a cover. The base has a bottom wall for holding the culture medium and the like, and a circumferential sidewall extending upwardly from the bottom wall and attached thereto. The base further incorporates a flange extending outwardly from the lower edge of the outer periphery of the sidewall. The outer periphery of the base sidewall is provided with a generally perpendicular surface along the lower edge thereof. The cover has a top wall, which has a larger diameter than the base sidewall, and a circumferential sidewall extending downwardly from the top wall and attached thereto. The cover is provided with a plurality of projections on the inner surface of the sidewall to engage the generally perpendicular surface of the lower edge of the outer periphery of the base sidewall. The projections have a diameter less than the diameter of the generally perpendicular surface of the lower edge of the outer periphery of the base sidewall to provide a biasing force to retain the cover on the base when the projections engage the generally perpendicular surface of the lower edge of the outer periphery of the base sidewall.