Del. Code tit. 10 § 3915
In any action by or against any corporation, the plaintiff may specifically require the defendant or defendants to deny the allegation of the incorporation and existence of the corporation by affidavit filed with the answer, by the specific notation of the need for denial by affidavit within the paragraph alleging the corporate existence. Any defendant so answering shall deny the incorporation and existence of the corporation as alleged, and stating to the best of affiant's knowledge whether there is any corporation existing which has a relationship to the subject matter of the action. Such affidavit may be made by the president, secretary, treasurer or any director of any corporate defendant. Where plaintiff has complied with this section, failure of any defendant to file an affidavit with its answer shall be deemed an admission of existence of the corporation as alleged.
10 Del. C. § 3915