Documentation, sample traceability, control selection and reproducibility habits that make preclinical peptide work defensible under review.
Documentation that survives review
- One record per batch: compound, quantity, supplier, batch code, arrival date, storage location.
- One record per preparation: diluent, volume, resulting concentration, date, operator.
- One record per experiment: batch used, aliquot, conditions, controls, raw output location.
- Certificates of analysis stored with the batch record, not in a mailbox.
Traceability
Any result should be traceable backwards to a specific vial and forwards to a specific dataset. In practice this means the batch code appears in the experimental record, not just on the invoice. Where a study spans months, keep it on a single lot; where that is impossible, record the changeover date explicitly so it can be tested as a variable later.
Controls and reproducibility
- Include a vehicle control prepared from the same diluent lot as the test article.
- Where possible include a reference compound with known behaviour in your model.
- Run enough replicates that a single anomalous preparation is visible as such.
- Blind analysis where the endpoint involves judgement.
- Repeat key findings with a fresh preparation before treating them as established.
Common avoidable errors
- Assuming nominal vial content equals net peptide content in quantitative work.
- Shaking rather than swirling during reconstitution.
- Repeated freeze-thaw of a single stock vial across weeks.
- Mixing batches mid-study without recording it.
- Relying on a generic certificate that does not carry the vial’s batch code.
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