AUDIT MicroControls announces a new addition to its line of calibration verification and linearity products—the Beta-Hydroxybutyric Acid Linearity, 5 levels. The product is intended to simulate human patient serum samples for the purpose of determining linearity, calibration verification, and verification of reportable range for beta-hydroxybutyric acid. Available in packages of five 1 mL vials, this liquid product has a shelf life of two years and an open vial stability of seven days when stored at 2-8°C.