Ohio Rev. Code Ann. § 3111.43

If a child support enforcement agency is asked to determine the existence or nonexistence of a parent and child relationship, the administrative officer shall provide notice of the request pursuant to the Rules of Civil Procedure to the natural mother of the child who is the subject of the request, each man presumed under section 3111.03 of the Revised Code to be the father of the child, and each man alleged to be the natural father. If the agency is unable to obtain service of process on the presumed father, alleged father, or natural mother within the time prescribed by section 3111.41 of the Revised Code, the agency shall proceed with genetic testing of all of those persons who are present on the date scheduled for the testing.