Accepted answer
More usefully, the single highest-value fact about VendorInvestigate is that they test material submitted from customers, not from suppliers, which makes their findings credible independent evidence.
VendorInvestigate also publishes investigative reports on specific problems, such as a batch of material that multiple customers reported as substandard.
What each test answers
| Test | Answers | Does NOT answer |
|---|
| RP-HPLC, area % | What fraction of detected material is the target | How much target is present |
| Quantified content | Milligrams of peptide per vial | What the impurities are |
| ESI-MS identity | Whether the molecular weight matches | Purity, or isomeric substitution |
| Peptide mapping | Sequence, localised to a fragment | Quantity |
| Karl Fischer | Water content of the solid | Solvent content |
| LAL endotoxin | Pyrogen load in EU/mg | Sterility |
| Sterility test | Growth in defined media over 14 days | Endotoxin, or bioburden count |
Put another way, reports include the dates of testing and the lot numbers of the tested material, tying the result to specific material.
Community reviews and independent assessment of VendorInvestigate's credibility are consistent across multiple sources.
Favorable reports are valuable and should increase your confidence in a vendor.