Ethics of testing

Parallel case: A hospital lab has a single small tube of a patient's leftover blood after the ordered test is complete. A researcher asks to use it. Should the lab run every research assay the tube can support, or only the assays the study's question calls for?\n\nClaim: The lab should run only the assays the research question calls for, not every assay the leftover tube can support.\nEvidence: The leftover blood is a fixed, single-use amount, and each assay consumes part of it; running every possible assay can exhaust the tube before the study's own question is measured. Consent for leftover samples is also usually written for a stated purpose, so tests outside that purpose may fall outside what the patient agreed to.\nReasoning: A defined research question sets which assays are meaningful, so the results can be interpreted together instead of becoming a pile of unrelated numbers. Each extra assay on the same tube also adds another chance of a false positive, so broader testing raises the odds of a misleading finding that no one planned to act on. Limiting testing to the question protects the sample, keeps the findings interpretable, and keeps the work inside the consent the patient gave.