No, a specific working example is not required to satisfy the best mode requirement in a patent application. The MPEP 2165.01 provides clear guidance on this matter: "There is no statutory requirement for the disclosure of a specific example — a patent specification is not intended nor required to be a production specification. In re Gay, 309 F.2d 768, 135 USPQ 311 (CCPA 1962)." Furthermore, the MPEP clarifies that: "The absence of a specific working example is not necessarily evidence that the best mode has not been disclosed, nor is the presence of one evidence that it has. Best mode may be represented by a preferred range of conditions or group of reactants." This means that inventors can satisfy the best mode requirement through various forms of disclosure, not necessarily through a specific working example. To learn more: best mode patent disclosure working example patent application