Certificates of Analysis

Every batch of material Santa Cruz Peptides releases is tested by independent third-party laboratories before it is offered for sale. This page is the index for those records. As batch certificates are published they will appear in the table below, each one tied to the specific lot it describes rather than to the compound in general.

What a certificate of analysis records

A certificate of analysis, usually shortened to COA, is the analytical summary a laboratory issues for one specific batch of material. That distinction matters more than it first appears. A COA is not a description of what a compound is supposed to be. It is a record of what was actually measured in one production run, on a stated date, using a stated method. Two batches of the same peptide, made the same way in the same facility, will produce two different certificates.

A useful certificate identifies the material and the batch, states the analytical methods applied, and reports what those methods returned. For synthetic peptides that normally means two questions answered by two different instruments: whether the material is the intended molecule, and how much of the preparation is that molecule rather than something else.

A specification sheet is a different document. A specification states the threshold a batch has to meet before it is released. A certificate states what the batch actually did. Researchers evaluating material should read both, and should treat the certificate as the document that carries the evidence.

Batch certificate library

Certificates are indexed by compound and batch identifier. Where a batch has a published certificate, the final column links to the document.

Compound	SKU	Batch	Test date	HPLC purity	Certificate
No batch certificates have been published to this page yet. To ask about the certificate covering a particular lot, use the contact form.

How identity and purity are established

High-performance liquid chromatography

HPLC answers the purity question. A sample of the preparation is dissolved and driven under pressure through a column packed with a stationary phase, usually a silica support carrying long hydrocarbon chains. Components in the mixture interact with that phase to different degrees, so they emerge from the column at different times. A detector at the outlet records what leaves and when, producing a trace of peaks.

The target peptide appears as one peak. Deletion sequences, truncated chains, residual reagents and synthesis by-products appear as others. Purity is reported as the area of the target peak expressed as a percentage of total peak area. A figure of greater than 98 percent means the target accounts for more than 98 percent of what the detector recorded.

Mass spectrometry

Mass spectrometry answers the identity question, which chromatography alone cannot. The instrument ionises the sample and measures mass-to-charge ratio, returning an observed molecular weight. That figure is compared against the weight calculated from the intended amino acid sequence. Agreement between the two is what establishes that the peak isolated by HPLC is the molecule it is meant to be.

The two techniques are complementary and neither substitutes for the other. Chromatography can show a single clean peak belonging to a compound that is not the target. Mass spectrometry can confirm the target is present in a preparation that is substantially contaminated. A certificate reporting both is answering both questions.

Reading a purity figure critically

Purity percentages are easy to quote and easy to misread. Three points are worth holding onto.

First, the figure depends on the detector. Most peptide HPLC uses ultraviolet detection at a wavelength where the peptide bond absorbs. Impurities that absorb weakly at that wavelength contribute less peak area than their actual share of the mass, so a reported figure describes what the detector could see rather than the complete composition of the vial.

Second, purity is not potency, and it is not water content. A preparation reported at high chromatographic purity may still carry residual solvent, counter-ions or moisture. Those are measured by separate methods when they are measured at all.

Third, the difference between purity grades is experimentally meaningful. Solid-phase synthesis assembles a chain one residue at a time, and small coupling failures accumulate as closely related sequences that are difficult to separate. Work run at 85 percent purity is not the same work as at 98 percent, and discrepancies between laboratories often trace back to material rather than method. This ground is covered further in the frequently asked questions and across the Peptide Research Library.

Requesting a certificate for a specific batch

Certificates are batch-specific, so an enquiry needs the batch identifier for the vial in question. Questions about a particular lot can be sent through the contact form. Compound-level background for the catalogue is collected in the research guides, and the full catalogue is listed under all research peptides.

Frequently Asked Questions

For Research Use Only

All compounds referenced on this page are supplied strictly for laboratory research purposes. They are not drugs, foods, cosmetics, or dietary supplements, and are not intended to diagnose, treat, cure, or prevent any disease. They are not for human or veterinary consumption. This page describes analytical testing methods for educational purposes and does not constitute guidance on use of any kind.