A lab notebook and chain of custody for reference materials

A reference material is only useful if you can say what it is and where it has been. The supplier answers the first question with a certificate of analysis for the lot — see lot numbers and lot discipline. The laboratory answers the second with its own records. If a result is ever questioned, the chain runs backwards: result → notebook entry → vial → lot number → certificate. Any missing link and the result cannot be defended.

The receiving entry is the anchor for everything that follows. Record, the day the parcel arrives:

• Date received and the order number.
• Compound name as printed on the vial, lot number, quantity and number of vials.
• Condition on arrival: seal intact, contents dry, packaging undamaged — see inspecting a vial on arrival.
• Storage location and the storage condition stated on the certificate.
• Where the certificate is filed.

A simple inventory table — one row per vial — does this well. Give each vial an internal identifier if the laboratory holds more than one of the same lot.

Storage records are mostly about not needing to open the freezer. The inventory should say where a vial is precisely enough that it is retrieved once. If the storage unit is temperature-logged, the log is part of the record; if a vial is moved, the move is recorded with a date. A vial that has spent time outside its stated condition is a vial whose history matters, and the record is the only place that history exists. See storing lyophilized reference materials.

Every time a vial is retrieved, the entry says who, when, what was done, and any calculation performed, with units on every term. Concentration and dilution arithmetic goes on the page, not on a scrap of paper — see concentration units. The entry also records the pipettes and balances used by identifier, so that an instrument problem discovered later can be traced to every result it touched. What is done with the material is governed by the laboratory's own procedures; we publish no preparation or usage instructions of any kind.

The last entry closes the chain: date, what was disposed of, the waste stream used, and who signed it off. An inventory row that ends in a disposal entry is complete. One that just stops is a question waiting to be asked. Disposal itself follows the laboratory's chemical waste procedure and local regulation — see record-keeping and disposal for research materials.

Either works; the requirement is the same. Entries are made at the time, are dated, identify who made them, and cannot be altered without the alteration being visible. A bound paper notebook with numbered pages does this by construction. An electronic notebook does it by audit trail. A spreadsheet on a shared drive does it only if the laboratory disciplines itself, which is why many laboratories keep the inventory in a spreadsheet and the narrative in a notebook. Whatever the medium, the file for a lot should be findable by lot number, because that is the identifier printed on the vial and on the certificate. Storage of the records follows the same logic as storage of the material: one known place, retrieved when needed. The quality page describes what the certificate contains; the notebook is where the laboratory's half of the record lives.

File the certificate of analysis for each lot alongside the inventory, by lot number. If a certificate is missing, contact support with the lot number and it will be sent the same business day. A laboratory that can produce, for any vial on its shelf, the certificate for that lot and the entries for its arrival, storage and handling is a laboratory whose results can be defended. Everything sold on this site is supplied for in-vitro laboratory research only, under the terms on the research use only page.