Systematic internal standard variability and issue resolution: two case studies
Related Experiment Video
Updated: Jan 6, 2026

Simulation of a Scaled Assembly Process with Collaboration of a Robotic Arm and Monitoring through a Vision System for Quality Control
Published on: August 29, 2025
1Development Bioanalysis, Janssen Research & Development, A division of Janssen Pharmaceutica NV, Turnhoutseweg 30, 2340 Beerse, Belgium.
Abstract:
Two case studies are presented of validated assays where the internal standard showed high variability, and there was a clear response difference between study samples and standards and quality controls. In the first case a co-eluting peak boosted the stable isotope labeled internal standard response in samples from hepatically impaired subjects. In the second case the blank plasma matrix suppressed the structural analog internal standard response. For both assays the issue could be resolved by adapting the chromatographic conditions and re-validating the assay (case 1) or by diluting the study samples with blank plasma (case 2).
More Related Videos
Related Concept Videos
Systematic Error: Methodological and Sampling Errors
Sampling errors originate from improper sampling methods or the wrong sample population. These errors can be minimized by refining the sampling strategy. Defective instruments or faulty calibrations are the sources of instrumental...
Random and Systematic Errors
Uncertainty in Measurement: Accuracy and Precision
Testing a Claim about Standard Deviation
The hypothesis testing for the claim of population standard deviation (or variance) requires the data and samples to be random and unbiased. The population distribution also must be normal. There is no specific requirement on the sample size as the estimation is based on the chi-square distribution.
As a first step, the hypothesis (null and alternative) concerning the claim about...
Variability: Analysis
The range is a simple measure of variability, indicating the difference between the highest and...
Empirical Method to Interpret Standard Deviation
This rule is used widely in statistics to calculate the proportion of data values...

