ACE2 Calibration Reagent 3 is a serum-based calibrator for the V-PLEX COVID-19 ACE2 Neutralization Kits. The ACE2 Calibration Reagent 3 demonstrates neutralizing activity against Spike and RBD antigens from the following Omicron sublineages: B.1.1.529, BA.1, BA.1.15, BA.2, BA.2.12.1, BA.2.75, BA.2.75.2, BA.2.86, BA.3, BA.4, BA.4.6, BA.5, BF.7, BN.1, BQ.1, BQ.1.1, EG.5.1, FL.1.5.1, XBB.1, XBB.1.16, XBB.1.16.1, XBB.1.16.6, XBB.1.5, and XBB.2.3.