Commissioning an independent peptide test: what to order and what it costs

Decide what question the test must answer

Order tests by the question, not by habit. Identity asks whether the expected molecule is present: mass spectrometry. Purity asks what share of the peptidic signal is the target: HPLC. Quantity asks how much peptide is in the vial: amino acid analysis or nitrogen analysis, sometimes combined with water and counter-ion tests. Endotoxin asks whether the material carries bacterial endotoxin that could affect an assay.

Most supplier certificates cover identity and purity only. If your concern is that the vial is the wrong compound, one mass spectrometry run may be enough. If your concern is concentration in your experiments, purity alone will not answer it.

Published rates we could verify

Commercial contract laboratories usually quote peptide testing on request. Bio-Synthesis, for example, lists amino acid analysis, HPLC, MALDI-TOF and LC-MS, counter-ion, water content and endotoxin assays on its analytical services page without prices. [3] The clearest public numbers we found came from university core facilities that sell services to outside users.

Ohio State's Campus Chemical Instrument Center lists rates effective 1 July 2025 in three tiers named internal, external academic and external industry. The page does not label each price block, so the mapping below follows the order the tiers are listed; confirm with the facility before budgeting. [1] The Medical University of Innsbruck Protein Core Facility list, valid from 9 September 2024, quotes member prices and bills external collaborators at 1.5 times (academic or non-profit) or 2 times (profit organisations). [2]

Budget for one lot

The table builds three budgets from the Innsbruck for-profit rates, which were the only list we found covering MS, HPLC and amino acid analysis together. Courier, VAT, data-analysis time and any setup minimums are extra, and Innsbruck's list is written for collaborators, so ask whether it accepts samples from outside buyers at all. [2]

Two details change the result. Innsbruck's amino acid analysis excludes proline and cysteine, so peptide content is calculated from the other residues. [2] And an HPLC run price covers the instrument run; ask whether the report will include the chromatogram, integration and a purity figure for your peptide, or only raw data.

How much sample each test needs

Sample mass is often the real constraint. Bio-Synthesis recommends at least 0.1 mg for mass spectrometry, 0.2 to 0.5 mg for analytical HPLC and at least 0.5 mg for amino acid analysis. [3] For Karl Fischer water it recommends roughly 10 to 20 mg per test in its submission guidance and 5 to 10 mg in its FAQ. [4]

So an identity, purity and quantity panel needs roughly 0.8 to 1.1 mg, while adding Karl Fischer can push the requirement past 10 mg. If each vial is small, you may need to sacrifice several vials from the same lot, which also adds to the cost. Confirm the laboratory's own minimums before shipping; they vary.

Choosing the laboratory

Price lists say nothing about accreditation. We did not see an ISO/IEC 17025 scope on the rate pages above, and the Bio-Synthesis page we read lists ISO 9001:2015 and ISO 13485:2016 certifications, which are quality-management certifications rather than a testing-laboratory accreditation. [1] [2] [3] If your file needs an accredited result, find accredited laboratories through the ILAC signatory search and the accreditation bodies' directories, then check that the scope lists the specific test. [5]

Some suppliers point buyers to independent testing themselves. Peptides EU says researchers wanting additional assurance may submit samples to an accredited independent laboratory of their choice. [6] Ask the supplier before ordering whether it will accept your laboratory's result if it disagrees with its certificate, and get the answer in writing.

Quotation checklist

Keep the quotation with the lot record so the cost of verification is visible when comparing suppliers. This guide covers laboratory testing of a research material, not any use of it.

• Peptide sequence, modifications and salt form, so the laboratory computes the right expected mass.
• Tests requested and the question each answers.
• Whether results come with the raw spectrum and chromatogram, not only a summary.
• Sample amount per test and whether one aliquot can serve several tests.
• Turnaround time and whether rush service costs more.
• Per-sample price, setup or minimum fees, and the outside-user multiplier.
• Accreditation body, certificate number and scope line for each test, if you need accredited results.
• Shipping conditions the laboratory requires for receipt.