Audit MicroControls Inc, Eatonton, Ga, has added to its line of calibration verification, linearity, and daily quality control products with the extended Linearity FD brain natriuretic peptide (BNP) control. The lyophilized product is intended to simulate human patient serum samples for the purpose of determining linearity, calibration verification, and verification of reportable range. Consisting of five levels that demonstrate a linear relationship to each other when assayed for BNP-32 and NT-Pro BNP, the product has an open-vial stability of 2 days for BNP-32 and 5 days for NT-Pro BNP when stored at 2–8°C. Report results are stored on the Auditor QC, a free online, real-time data reduction program. For more information, visit Audit MicroControls.