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RegisterOdd QC values but not outliers [Bioanalytics]
Dear all,
I tried to look through all related topics in the forum and found some questions very closed with my issue, however, I could not get the final answer. Could you please advise what I should do in my case: My lab is validating a method for a compound in human plasma. Two core runs have been done (by 2 different analysts), QCs in 3 levels low, medium and high (6 replicates at each level) past with flying colours (all around 100% for accuracy). No carry-over observed. BUT: core run 1 has one LLOQ 498% and one LLOQ 727%, the other four LLOQs have good accuracy 〜100%. Core run 2 has five LLOQs with accuracy 〜100% and one LLOQ 3000%. For core run 2, 3000% can be regarded as outlier (from Grubb's test - calculated by Prism) but for core run 1, both values 498% and 727% are not outliers.
We couldn't figure it out whether there are any sample processing errors so we could't exclude those values from accuracy and precision calculation for LLOQ, it means the core run 1 failed.
We stop validation at this point to have investigation. Much appreciated if you can help with any clues for this situation.
Thanks and best regards,
Thi Nguyen
I tried to look through all related topics in the forum and found some questions very closed with my issue, however, I could not get the final answer. Could you please advise what I should do in my case: My lab is validating a method for a compound in human plasma. Two core runs have been done (by 2 different analysts), QCs in 3 levels low, medium and high (6 replicates at each level) past with flying colours (all around 100% for accuracy). No carry-over observed. BUT: core run 1 has one LLOQ 498% and one LLOQ 727%, the other four LLOQs have good accuracy 〜100%. Core run 2 has five LLOQs with accuracy 〜100% and one LLOQ 3000%. For core run 2, 3000% can be regarded as outlier (from Grubb's test - calculated by Prism) but for core run 1, both values 498% and 727% are not outliers.
We couldn't figure it out whether there are any sample processing errors so we could't exclude those values from accuracy and precision calculation for LLOQ, it means the core run 1 failed.
We stop validation at this point to have investigation. Much appreciated if you can help with any clues for this situation.
Thanks and best regards,
Thi Nguyen
Complete thread:
- Odd QC values but not outliersThi Nguyen 2017-09-18 14:43
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Odd QC values but not outliers Ohlbe 2017-09-18 15:53
- Odd QC values but not outliers Thi Nguyen 2017-09-19 13:14
- Odd QC values but not outliers ElMaestro 2017-09-19 13:38
- Odd QC values but not outliers Ohlbe 2017-09-19 13:49
- Odd QC values but not outliers Thi Nguyen 2017-09-19 13:14
- Odd QC values but not outliers Ohlbe 2017-09-18 15:53
Ing. Helmut Schütz