Ohio Rev. Code § 3111.10: Evidence of paternity.

In an action brought under sections 3111.01 to 3111.18 of the Revised Code, evidence relating to paternity may include:

(A) Evidence of sexual intercourse between the mother and alleged father at any possible time of conception;

(B) An expert's opinion concerning the statistical probability of the alleged father's paternity, which opinion is based upon the duration of the mother's pregnancy;

(C) Genetic test results, weighted in accordance with evidence, if available, of the statistical probability of the alleged father's paternity;

(D) Medical evidence relating to the alleged father's paternity of the child based on tests performed by experts. If a man has been identified as a possible father of the child, the court may, and upon the request of a party shall, require the child, the mother, and the man to submit to appropriate tests. Any fees charged for the tests shall be paid by the party that requests them unless the court orders the fees taxed as costs in the action.

(E) All other evidence relevant to the issue of paternity of the child.