Analytical documentation is only useful if the material it describes can be traced in practice. The following practices are common in laboratories that handle lyophilised reference materials regularly.
Label on receipt
Record the date of receipt on the vial label or in the batch log as soon as the shipment is unpacked. The COA gives the date of analysis; only your own record tells you when the material entered your storage.
Equilibrate before opening
Lyophilised powder held in a freezer should be brought to room temperature before the vial is opened. Opening a cold vial allows condensation to form inside, introducing moisture into a material that was deliberately dried.
Plan aliquots before reconstitution
Repeated freeze-thaw cycles are best avoided. Where a material will be used across several sessions, planning single-use aliquots at the point of reconstitution reduces repeated handling and limits the number of times a stock solution is cycled.
Storage conditions
Lyophilised material is typically held refrigerated or frozen, dry and out of direct light. Reconstituted solutions are usually held at 2-8°C and used within a period defined by the laboratory protocol rather than by the supplier.
Records worth keeping
- Batch number and receipt date for each vial
- Certificate of Analysis filed against the batch
- Date of first opening and date of reconstitution
- Solvent system and concentration used for any working solution
- Disposal date and method
Matching results to batches
When experimental results are reported, the batch number is what allows a result to be revisited later. A result recorded without a batch reference cannot be traced back to a certificate, and the analytical data becomes effectively unusable.
Documentation limits
Supplier documentation describes the material at release. It does not describe stability in your storage, the effect of your reconstitution protocol, or suitability for your assay. Those questions are answered by your own laboratory practice and, where needed, by your own verification work.