A comparison table places chromatographic purity and net peptide content in one column. Both are percentages, but the reports define their denominators differently. How should the table be repaired?
| Field | Scope |
|---|---|
| Subject | Two laboratories, two percentages: are they measuring the same thing? |
| Exercise | Discuss the stated question; distinguish sources, interpretations and unresolved points. |
Create separate columns for the quantity measured, method, units and denominator. Do not subtract the two percentages as though they represented a disagreement about the same measurement.
Keep the original reported values beside any reformatted presentation. A conversion or interpretation needs a documented basis; it should not silently replace the source.
Before comparing laboratories, ask whether sample handling, method conditions and reporting definitions are available. Missing details should be visible in the table.
Use a comparison-status column: directly comparable, comparable with stated qualifications, or not established. Explain the reason for each label.
An apparent difference can motivate a method question without proving that either laboratory is wrong. The appropriate next step is clarification from the reporting laboratory.