ARCHITECT B12 Reagents, List 6C09-20 (4 x 100 tests) and List 6C09-25 (100 tests); Abbott Laboratories, Abbott Park, IL 60064 USA; Abbott, Max-Planck-Ring 2, 65205 Wiesbaden, Germany

Changes in the ARCHITECT B12 Reagent lots may adversely affect the shape of the calibration curve, over time. These changes may produce controls out of range low and similar decreases in patient sample values prior to current expiration of the reagents.

Abbott affiliates in Canada, Germany, Singapore, Hong Kong, Australia, New Zealand and Japan were e-mailed copies of the recall letter on 8/19/04 for translation where needed and dissemination to their accounts receiving the suspect lots. The end users were advised of the potential for changes in the reagents over time that affect the shape of the calibration curve, producing controls out of range low and similar decreases in patient sample values. The accounts were instructed to manually update the expiration dates for the reagent lots according to the chart given in the recall letter for any of the affected lots remaining in inventory. The expiration date reported by the Architect instrument must also be manually updated.