Quality control: from raw material to certificate

1. Goods receipt and records

Every incoming delivery is recorded on arrival: product, quantity, delivery date and storage location are documented, and every vial keeps the label it was filled with. Nothing is moved into stock before that record exists. It is what allows a vial in the laboratory to be traced back to a defined delivery and to the test report that belongs to it.

2. Sampling

For the regular external analysis, vials are taken from the delivery and sent to the laboratory. They come from the same fill as the goods that are later sold, which is what makes a result meaningful at all: an analysis applies only to the material the sample was drawn from, never to a product name in general. Further vials from the same fill are set aside and kept in store.

3. External analysis

An independent laboratory tests identity, purity, heavy metals and endotoxins. The laboratory has no connection to our company: it receives the samples, applies its own methods and issues the report. The results are not post-processed.

4. What the individual tests measure

• Identity – mass spectrometry measures the mass-to-charge ratio of the ionised sample; the molecular mass calculated from it is compared with the mass expected for the sequence.
• Purity – HPLC separates the sample on a column and reports the area of the main peak as a percentage of the total peak area at the detection wavelength used.
• Heavy metals – elemental residues from synthesis, reagents or equipment, reported as a concentration per unit weight.
• Endotoxins – lipopolysaccharide fragments of bacterial origin, reported in endotoxin units per milligram.

The two analytical methods are explained in the guide on HPLC and mass spectrometry, and what a purity figure covers and leaves out in the guide on purity and impurities.

5. Assessing the results

Where a report is available, the result is considered sound when the measured mass corresponds to the theoretical mass of the sequence within the tolerance of the method, and when the purity reaches the value stated on the product page. Both conditions have to hold together. A high purity figure on its own says only that one substance dominates the chromatogram, not which substance it is, and a correct mass says nothing about the proportion of by-products beside it. If a report shows that one of the two is not met, the material it refers to is not sold.

6. Publication and the “pending” marking

Every certificate of analysis names the material it refers to, the method and the test date, so that it can be compared with the label on the vial. The certificates that are available are published in the lab area and linked from the product page. Testing is carried out at regular intervals by the external laboratory; it is not a release step performed before each individual sale, and no claim is made here that every delivery has been tested. Where no report has been published for a product, it is marked as “pending”.

7. Storage and traceability

Goods are stored cool, dry and protected from light, under the same conditions described for the laboratory in the guide on storing lyophilised peptides. Product, delivery and storage location stay linked in the records, and the vials set aside remain available, so that a later question about a delivery can be examined against material from the same fill.

8. What can be checked independently

1. The product named on the vial label against the material named on the report.
2. The test date against the delivery date of the goods.
3. The name of the laboratory and the methods stated on the report.
4. Whether a chromatogram or spectrum is shown, not just a bare figure.

Which entries appear on such a report, and how to tell a complete one from a thin one, is set out in the guide on reading a certificate of analysis.