(MAB).2 In that proceeding, Hybritech, alleging that the manufacture and sale of Monoclonal Antibodies, Inc.’s (Monoclonal) diagnostic test kits infringed claims of the ’110 patent, on March 2, 1984, brought action in district court against Monoclonal seeking both monetary and injunctive relief.3 The United States District Court for the Northern District of California concluded that the claimed subject matter of the ’110 patent was anticipated under 35 U.S.C. § 102(g). The district court, in that case, also held the claims of the ’110 patent invalid for obviousness under 35 U.S.C. § 103. In addition, the district court also invalidated the patent on various grounds based on 35 U.S.C. § 112, first and second paragraphs. On appeal to this court, we reversed in all respects the judgment of the district court holding the claims of the ’110 patent invalid.
Subsequent to receiving favorable results on appeal to this court in its litigation with Monoclonal, Hybritech on November 14, 1986, brought a patent infringement action against Abbott seeking both monetary and injunctive relief on grounds that Abbott manufactured and sold diagnostic test kits that infringed claims of the ’110 patent. Abbott responded to Hybritech’s complaint by filing a counterclaim seeking a declaratory judgment that claims of the ’110 patent were invalid and not infringed by Abbott.
With respect to Hybritech’s request for a preliminary injunction, the parties conducted limited discovery and submitted memo-randa and appendices to the district court. After briefing on the motion was complete but before the district court rendered a decision on the motion, the United States Patent and Trademark Office, on April 8, 1987, declared an interference as to the ’110 patent among Hybritech and La Jolla Research Foundation, both junior parties, and Hoffmann-LaRoche, Inc., the senior party. Abbott filed a motion for a stay of the district court action pending the outcome of the interference proceeding; however, this motion was denied by the district court.
On April 23-24, 1987, the district court heard oral argument on the preliminary injunction motion and, at the conclusion of the hearing, the district court rendered an oral ruling, including both oral findings of facts and conclusions of law, that Hybri-tech’s motion for a preliminary injunction should be granted. At this time, the district court expressed its intent to put its oral findings and conclusions into writing. On June 12, 1987, the district court formally entered the injunctive order. In addition to entering the injunction order, the district court granted Abbott’s motion to stay the preliminary injunction pending the outcome of this appeal. Abbott, on July 10, 1987, filed its notice of appeal on the injunctive order with this court. On July 14, 1987, the district court entered its written findings of facts and conclusions of law based on its prior oral findings of facts and conclusions of law issued April 24th.
III. Analysis
Our review of a district court’s grant of a preliminary injunction pursuant to 35 U.S.C. § 283 is limited to determining whether, in granting the preliminary injunction, the district court abused its discretion, committed an error of law, or seriously misjudged the evidence.4 Applying this standard of review to the proceeding before us, we cannot conclude, as urged by Abbott, that the district court abused its discretion by granting Hybritech’s motion for a preliminary injunction.
At the threshold in reaching Abbott’s arguments on the merits, we address the procedural issue raised by Abbott whether, for purposes of our review, the district court’s oral ruling, issued April 24,
2
Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 231 USPQ 81 (Fed.Cir.1986) (MAB), cert. denied, — U.S. -, 107 S.Ct. 1606, 94 L.Ed.2d 792 (1987).
3
Hybritech Inc. v. Monoclonal Antibodies, Inc., 623 F.Supp. 1344, 227 USPQ 215 (N.D.Cal.1985).
4
. T.J. Smith & Nephew Ltd. v. Consolidated Medical Equip., Inc., 821 F.2d 646, 647, 3 USPQ2d 1316, 1317 (Fed.Cir.1987).