Laboratory guides
Aliquoting reconstituted research solutions
An aliquot is an identified portion of a preparation. Its usefulness depends on matching the planned work and preserving traceability; dividing a vial does not demonstrate stability or make every transferred volume exact.
Source editorial review:
Plan from the experiment, not the container
Define the preparation needed for each session and check whether the instrument can transfer that volume within its verified range. The smallest aliquot is not always best: a portion that cannot be measured or recovered adequately adds uncertainty.
Case: insufficient material for the final tube
Do not top up the last container just to make it “look the same”. Compare starting volume, recorded transfers and observed discrepancies. An incomplete volume must be identified as such; matching fill heights visually establishes neither concentration nor traceability.
If the method includes a reserve or volumetric check, document it before splitting. Avoid inventing a fixed loss factor for every container and material.
Each derivative needs a readable link
Assign child identifiers linked to the stock solution and retain the source lot in the record. Record preparation, storage conditions and use events. Aliquoting can reduce repeated handling, but usable lifetime must be supported separately.
A record for this decision
How can each aliquot be traced to its parent solution?
| Field | What to document |
|---|---|
| Origin | Stock solution identifier, batch and nominal concentration. |
| Derivation | Transferred volume, any dilution and a new identifier. |
| History | Date, operator, container and storage. |
When to leave the decision open
Dividing a solution does not validate stability or exclude losses. Record transfers and do not automatically give an aliquot the solid material’s period of use.
Questions and answers
Do all aliquots inherit the original vial date?
They retain that history, but their preparation and storage need separate records. Splitting alone must not assign a new usable lifetime.
Can tubes be identified by position alone?
Position helps locate them but does not replace unambiguous identification linked to the preparation record.