Audit MicroControls Inc, Eatonton, Ga, has expanded its line of calibration verification and linearity controls with the Linearity LQ set of ammonia and ethanol controls for Roche systems. The set of controls is designed to simulate human serum samples for determining linearity, calibration verification, and verification of the reportable range for quantitative assays performed on Roche clinical chemistry analyzers. The Linearity LQ set is a ready-to-use liquid product consisting of five levels that demonstrate a linear relationship to each other when assayed for ammonia and ethanol. The product has an open-vial stability of 2 days when stored at 2–8°C. For more information, visit Audit MicroControls.