Ohio Revised Code Title XXIII. Courts Common Pleas § 2317.47

Whenever it is relevant in a civil or criminal action or proceeding to determine the paternity or identity of any person, the trial court on motion shall order any party to the action and any person involved in the controversy or proceeding to submit to one or more blood-grouping tests, to be made by qualified physicians or other qualified persons not to exceed three, to be selected by the court and under such restrictions or directions as the court or judge deems proper. In cases where exclusion is established, the results of the tests together with the findings of the experts of the fact of nonpaternity are receivable in evidence. Such experts shall be subject to cross-examination by both parties after the court has caused them to disclose their findings to the court or to the court and jury. Whenever the court orders such blood-grouping tests to be taken and one of the parties refuses to submit to such test, such fact shall be disclosed upon the trial unless good cause is shown to the contrary. The court shall determine how and by whom the costs of such examination shall be paid.