US law requires that an inventor disclose the "best mode or method" known to him or her for carrying out the invention. This requirement is violated if the inventor knew of a superior method for carrying out the invention but concealed it by failing to disclose it in the patent application. If an inventor conceals the best mode of the invention, any patent resulting from it will be invalid. However, as long as an inventor has acted in good faith, the best mode requirement is met even if the inventor does not know of or fails to appreciate the best mode of the invention. Note, too, that even if deposit of a biological material is not needed for enablement, it may be needed to satisfy best mode.