- Assay anomaly (hypothetical run)
  - [Q @signal] Why did the treated samples produce a weaker signal?
    - [C answers @signal] The detection reagent degraded before the run.
      - [_ +> ^] Weak controls implicate the reagent only if they shared its lot.
        - [.] Positive controls were also weaker than their historical range.
        - [.] The controls used the same reagent lot as the treated samples.
          - [note] Confirm the lot numbers on the run sheet.
      - [G] The reagent was left at room temperature overnight.
      - [O] The low readings may instead be a plate-position effect.
        - [G] Most low readings occurred along the outer wells.
    - [note] Repeat with a fresh reagent and randomized well positions.