While the patent statute does not provide for product-by-process claims, the courts have long recognized the appropriateness of such claims. See, e.g., In re Thorpe, 777 F.2d 695, 697 (Fed. Cir. 1985); In re Brown, 59 C.C.P.A. 1036, 459 F.2d 531, 535 (1972); In re Steppan, 55 C.C.P.A. 791, 394 F.2d 1013, 1018 (1967). The purpose of product-by-process claims is to allow inventors to claim "an otherwise patentable product that resists definition by other than the process by which it is made."

In Scripps Clinic Research Found. v. Grenentech, the Federal Circuit held that "[s]ince claims must be construed the same way for validity and for infringement, the correct reading of product-by-process claims is that they are not limited to product prepared by the process set forth in the claims." 927 F.2d 1565, 1583 (Fed. Cir. 1991) (citing In re Thorpe, 777 F.2d 695 (Fed. Cir. 1985)). The following year, a different panel of the Federal Circuit decided Atlantic Thermoplastics Co., Inc. v. Faytex Corp., 970 F.2d 834 (Fed. Cir. 1992), reh'g en banc denied, 974 F.2d 1299.