121.0.2. In any prosecution under this Act, the certificate relating to the analysis of any machine required to be registered under this Act signed by an analyst of the laboratory referred to in section 52.15 shall be accepted as proof, until proof to the contrary, of the facts set forth therein and of the authority of the person who signed such certificate, without further evidence of his appointment or of his signature. The costs of such analysis shall also be included in the costs of the proceeding.