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Investigation summary: the complaint investigation for suspected false negative results when using bd max¿ cpo (ref.445262) kit lot 4194273 was performed by the review of manufacturing records, retain material inspection, review of customer¿s data and by the complaint¿s history review.The review of quality control records of bd max¿ cpo lot 4194273 revealed no anomalies that could explain the customer¿s negative results.The retain material of bd max¿ cpo from lot 4194273 was visually inspected showed no anomaly.However, kit lot 4194273 was expired at the time the complaint was investigated, and no conclusion was possible concerning performance.Customer reported one of their samples (last three digits of accession number #401) presented a positive curve in the vic channel (vim/imp-1-2 targets), but the software interpreted the result as negative.According to customer, this is an issue with the interpretation of a positive result with the bd max¿ cpo assay.They mentioned having cultured the sample, which tested positive and immunochromatography detected vim.Customer provided run files for run 291 from bd max¿ instrument ct3187 for the investigation.Manual pcr curve adjudication of the sample in position b8 revealed a weak pcr amplification curve with a late ct value and low endpoint.Despite the signal in the vic channel (vim/imp-1-2 targets), the result was negative by the bd max¿ because the signal did not reach the ct and endpoint threshold values to be considered valid by the algorithm.For sample b8 of run 291, the signal was too late, explaining the negative vim/imp-1-2 result.As stated in the instruction for use ¿limitations of the procedure¿ section, the bd max¿ system provides qualitative results.Any reported ct value or displayed curve should only be used to the purposes of laboratory quality control trending, research, and public health reporting.A negative result was the expected result in such condition.It must also be noted that limit of detection can vary between different assays and testing methods.Nevertheless, manual curve adjudication has limitations; visual examination of pcr curves for low signal is a conservative assessment of the data.There is no indication of a reagent issue based on the analysis of the complaints received for discrepant results on bd max¿ cpo kit lot 4194273.The root cause was not identified.However, a sample with a concentration beyond the ct values limits of detection of the assay is the most likely cause to explain the customer¿s discrepant results.Bd cannot confirm the complaint based on the investigation that was performed.Bd did not initiate a corrective and preventive action since no new hazard was identified.Bd apologizes for the inconvenience that this may have caused.Bd quality will continue to monitor for trends.
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