Accuracy vs. Precision in Peptide Testing
Accuracy and precision describe different aspects of analytical performance.
Accuracy
Accuracy is closeness to an accepted reference value. It may be evaluated through recovery, reference materials, or comparison with an established procedure.
Precision
Precision is closeness among repeated measurements. It includes repeatability, intermediate precision, and reproducibility.
Four possible outcomes
A method can be:
- accurate and precise
- accurate on average but imprecise
- precise but biased
- neither accurate nor precise
Practical example
If repeated assay values cluster tightly at 92% when the true value is 100%, the method is precise but inaccurate.
Frequently asked questions
Can averaging improve accuracy?
Averaging reduces random variation but does not remove systematic bias.
Is repeatability the same as reproducibility?
No. Reproducibility generally involves broader changes such as laboratories.
Can a method pass precision and fail accuracy?
Yes.
Why evaluate multiple levels?
Performance can differ across concentration.
Key takeaways
Precision shows consistency; accuracy shows correctness relative to a reference. Reliable peptide testing requires both.
References
- ICH Q2(R2). Validation of Analytical Procedures.
- ICH Q14. Analytical Procedure Development.
- FDA. Analytical Procedures and Methods Validation for Drugs and Biologics.
TSMS Labs educational disclaimer: For laboratory research and educational purposes only. Not for human consumption. This content is not medical, clinical, or regulatory advice.