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RegisterOdd QC values but not outliers [Bioanalytics]
Dear Thi Nguyen,
In addition to ElMaestro's comments and questions:
OK, so it doesn't look like a spiking error.
Right. My question was also: does the measured concentration of these problematic LLOQ samples match with the nominal concentration of e.g. HQC or CC7 or whichever other spiked sample ? It could be simply a labelling error after aliquoting, or taking the wrong sample out of the freezer.
OK. Could it be a contamination at some point ? How do you process the samples: manually, or in 96-well plates with robotic equipment, or what ?
In addition to ElMaestro's comments and questions:
❝ LLOQ and all other QCs (LQC, MQC, HQC) were prepared in bulk by spiking solutions into 10 ml plasma then aliquoted into small vials (enough for 2 replicates in assay) so LLOQ are homogenous, it shouldn't cause one very high, another from the same vial normal.
OK, so it doesn't look like a spiking error.
❝ And yes, the concentrations measured match with the nominal concentration (accuracy were quite good, most of them around 100%). The abnormal only happened with LLOQ, but not with any other QCs.
Right. My question was also: does the measured concentration of these problematic LLOQ samples match with the nominal concentration of e.g. HQC or CC7 or whichever other spiked sample ? It could be simply a labelling error after aliquoting, or taking the wrong sample out of the freezer.
❝ No carry-over was observed at all, and the LLOQ with high values were not following any ULOQ in the run.
OK. Could it be a contamination at some point ? How do you process the samples: manually, or in 96-well plates with robotic equipment, or what ?
—
Regards
Ohlbe
Regards
Ohlbe
Complete thread:
- Odd QC values but not outliers Thi Nguyen 2017-09-18 14:43 [Bioanalytics]
![[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 outliersOhlbe 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