These include (1) likelihood of success on the merits; (2) irreparable harm to the patentee if a preliminary injunction is denied; (3) a balance of the hardships to the parties as the result of granting or denying an injunction; and (4) the public interest weighing for or against issuance of a preliminary injunction in a particular case. See, e.g., PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1558 (Fed. Cir. 1996); Sofamor Danek Group, Inc. v. DePuy-Motech, Inc., 74 F.3d 1216, 1219 (Fed. Cir. 1996) (formulating the four inquiries as whether the movant can show: "(1) a reasonable likelihood of success on the merits, (2) an irreparable harm, (3) the balance of hardships tipping in its favor; and (4) a tolerable effect on the public interest," citing Hybritech, Inc. v. Abbott Labs., 849 F.2d 1446, 1451 (Fed. Cir. 1988)); Reebok, 32 F.3d at 1555 (also citing Hybritech); Intel Corp., 995 F.2d at 1568 (also citing Hybritech); New England Braiding Co., 970 F.2d at 882; Filmtec Corp. v. Allied-Signal, Inc., 939 F.2d 1568, 1571 (Fed. Cir. 1991); Chrysler Motors Corp. v. Auto Body Panels of Ohio, Inc., 908 F.2d 951, 952 (Fed. Cir. 1990). These factors must be balanced against each other and against the extent of the relief sought in the patentee's motion for preliminary injunction.

Id. at 1286 (quoting Intel Corp. v. ULSI Sys. Tech. Inc., 995 F.2d 1566, 1568 (Fed. Cir. 1993)). It is purely within the district court's discretion to grant or deny a preliminary injunction in a patent case, and review is made with an eye for abuse of that discretion. PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1560 (Fed. Cir. 1996). Despite the instruction that no one factor is dispositive, the likelihood of success and irreparable harm factors seem significantly more important.

Although Donovan correctly notes that a patent is presumed to be valid, 35 U.S.C. § 282, that presumption merely gives a patent holder the right to have validity judged by whether the challenger's evidence is sufficient to meet a clear and convincing standard. See PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1566 (Fed. Cir. 1996); New England Braiding Co. v. A.W. Chesterton Co., 970 F.2d 878, 882 (Fed. Cir. 1992) (noting that presumption of validity "acts as procedural device which places the burden of going forward with evidence and the ultimate burden of persuasion of invalidity at trial on the alleged infringer.").

Although Donovan correctly notes that a patent is presumed to be valid, 35 U.S.C. § 282, that presumption merely gives a patent holder the right to have validity judged by whether the challenger's evidence is sufficient to meet a clear and convincing standard. See PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1566 (Fed. Cir. 1996); New England Braiding Co. v. A.W. Chesterton Co., 970 F.2d 878, 882 (Fed. Cir. 1992) (noting that presumption of validity "acts as procedural device which places the burden of going forward with evidence and the ultimate burden of persuasion of invalidity at trial on the alleged infringer.").

The district court found that any asserted harm to LTC was “of lesser scope” than the harm to Celsis and also “protectable by a bond.” Hr'g Tr. 17:9–11 (citing PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558 (Fed.Cir.1996)). The district court did not clearly err in finding the balancing of harms favors Celsis. Absent a preliminary injunction, Celsis would lose the value of its patent as well as suffer the irreparable harms opined on by its expert.

"To anticipate a claim, a reference must disclose every element of the challenged claim and enable one skilled in the art to make the anticipating subject matter." PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1566 (Fed. Cir. 1996) (citations omitted). CCGroup argues that its expert, Dr. Bergeron, testified that the Cave Article teaches every limitation of Claim 1 of the '079 patent.

"[A] considerable amount of experimentation is permissible, if it is merely routine, or if the specification in question provides a reasonable amount of guidance with respect to the direction in which experimentation should proceed." PPG Indus. Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1564 (Fed. Cir. 1996) (quoting Ex Parte Jackson, 217 U.S.P.Q. 804, 807 (1982)). Enablement is determined as of the filing date of the patent application.

Anticipation is established if every element of a properly construed claim is present in a single prior art reference. See id.; see also PPG Indus., Inc. v. Guardian Indus. Corp., 75 F.3d 1558, 1566 (Fed. Cir. 1996); Scripps Clinic Research Found. v. Genentech, Inc., 927 F.2d 1565, 1576 (Fed. Cir. 1991). "There must be no difference between the claimed invention and the reference disclosure, as viewed by a person of ordinary skill in the field of the invention."

The question of undue experimentation is a matter of degree, and what is required is that the amount of experimentation not be “unduly extensive.” Chiron Corp. v. Genentech, Inc., 363 F.3d 1247, 1253 (Fed.Cir.2004) (quoting PPG Indus., Inc. v. Guardian Indus., Corp., 75 F.3d 1558, 1564 (Fed.Cir.1996)). For example, the fact that a clinician's involvement may be necessary to determine effective amounts of the single compound effervescent agent and its corresponding soluble acid source does not itself constitute undue experimentation.

See Morton Int'l v. Cardinal Chem. Co., 5 F.3d 1464, 1470 (Fed. Cir. 1993) (holding claims indefinite because one skilled in the art could not determine whether a given compound was within the scope of the claims). The criticality of sample preparation method also distinguishes this case from PPG Industries, Inc. v. Guardian Industries Corp., 75 F.3d 1558 (Fed. Cir. 1996). In that case, PPG accused Guardian of infringing its patent directed to a glass composition consisting of different ingredients and exhibiting an ultraviolet transmittance within a certain range.