Question 1

What is peptide testing?

Accepted Answer

Peptide testing is the laboratory analysis of a peptide sample to determine what it contains and whether it matches the compound it is claimed to be. Depending on the testing requested, analysis can evaluate identity, purity, concentration, molecular weight, impurities, and degradation products. Explore our Peptides & Bioanalytical testing services.

Question 2

Why are peptides tested?

Accepted Answer

Peptides are tested to verify that the material received is what the supplier claims it is and to assess its measurable analytical characteristics. Testing can confirm identity, measure purity or content, detect impurities and degradation products, verify molecular weight, and compare results with a supplier’s COA. Click here for an example of a Certificate of Analysis (COA) for Peptide Testing. Explore our Peptides & Bioanalytical testing services.

Question 3

How are peptides tested?

Accepted Answer

Peptide testing typically uses one or more analytical techniques selected according to the question being answered. HPLC separates sample components and is commonly used for chromatographic purity; mass spectrometry provides molecular-mass information; LC-MS combines separation and mass information. Read our Peptide Purity Verification Guide.

Question 4

What does peptide analysis test for?

Accepted Answer

Peptide analysis can evaluate identity, molecular weight, chromatographic purity, peptide content or concentration, impurities, and degradation. No single test necessarily answers every question, so a comprehensive analysis may combine multiple techniques. Browse our peptide catalog for compound-specific testing.

Question 5

How do you test peptide purity?

Accepted Answer

Peptide purity is commonly measured using HPLC or another appropriate chromatographic method. The sample is separated into components, the target peptide and other relevant peaks are detected and integrated, and the result is calculated according to the laboratory’s method.

Question 6

What does 99% peptide purity mean?

Accepted Answer

A reported 99% peptide purity generally means that approximately 99% of the relevant chromatographic signal is attributed to the target peptide under the specified method. It does not necessarily mean that 99% of the vial’s total mass is peptide. Try our Peptide Calculator.

Question 7

What is the difference between peptide purity and peptide content?

Accepted Answer

Purity describes the relative amount of target peptide in the analytical profile under a specified method. Content describes how much target peptide is actually present. A sample can have high chromatographic purity but lower-than-expected content because of water, counterions, salts, residual solvents, or other non-target material. Try our Peptide Calculator.

Question 8

What is the difference between HPLC and LC-MS?

Accepted Answer

HPLC is primarily a separation technique. LC-MS combines chromatographic separation with mass spectrometric detection. HPLC is useful for chromatographic purity, while LC-MS adds molecular-mass information that can support identity evaluation and impurity characterization. Read our Peptide Purity Verification Guide.

Question 9

Can HPLC confirm peptide identity?

Accepted Answer

HPLC retention time can provide supporting evidence for identity when compared with an appropriate reference under the same conditions. Retention time alone is generally less definitive than mass spectrometry, so HPLC and MS are often used together for stronger identity confirmation.

Question 10

How do you confirm peptide identity by mass spectrometry?

Accepted Answer

Identity can be evaluated by comparing the measured molecular mass with the expected mass of the claimed peptide. Where appropriate, fragmentation or MS/MS data can provide additional structural information. Chromatographic behavior and other analytical evidence may further strengthen identification.

Question 11

How do you verify a peptide COA?

Accepted Answer

Check that the COA identifies the specific product or batch, names the testing organization, describes the analytical methods, reports actual results, and includes supporting data where relevant. Independent testing of a sample from the same batch provides a stronger way to verify supplier claims than reviewing the COA alone. Click here to verify an Apollo Analytical COA.

Question 12

What should a peptide test report include?

Accepted Answer

A useful report should identify the sample, testing laboratory, dates, analytical methods, results, units, applicable specifications, supporting analytical data, and relevant limitations or qualifications. Click here for an example of a Certificate of Analysis (COA) for Peptide Testing.

Question 13

How much does peptide testing cost?

Accepted Answer

The cost depends on the type and number of analyses requested, number of samples, method-development needs, specialized requirements, and turnaround time. Pricing is generally based on the specific testing panel and sample requirements. View Apollo Analytical's Pricing page for more information.

Question 14

How long does peptide testing take?

Accepted Answer

Turnaround depends on the tests requested and whether an established analytical method is available for the peptide. Straightforward identity and purity testing can generally be completed faster than work requiring method development or specialized quantitative analysis. Apollo Analytical's standard turnaround is 5–10 business days from sample receipt. For time-sensitive programs, Rush Processing (3–5 business days) is available for a flat $250 add-on fee. Ready to start? Submit an order. Already submitted? Track your order.

Question 15

Where can I get a peptide tested?

Accepted Answer

Peptides can be tested by specialized analytical laboratories with appropriate instrumentation, methods, and peptide-characterization experience, such as Apollo Analytical. When choosing a laboratory, consider independent testing capability, clear methods, transparent reporting, relevant analytical expertise, quality systems, and appropriate accreditation where applicable. Click here for information on Apollo Analytical's ISO/IEC 17025 for Peptide Testing. View all Apollo Analytical services. In Arizona? Schedule a local sample pickup.

Question 16

What turnaround time can I expect for peptide analytical testing?

Accepted Answer

Our standard turnaround is 5–10 business days from sample receipt for most HPLC, ESI-MS, and purity analyses. Rush 3–5 business day service is available for time-sensitive submissions. Stability programs and custom method development follow project-specific timelines we confirm in writing before work begins.

Question 17

What documentation do I receive with my results?

Accepted Answer

Every test ships with a signed, scientist-reviewed Certificate of Analysis (CoA) at no extra cost. CoAs include method details, raw chromatograms, mass spectra, and pass/fail determinations against your specifications. Each CoA carries a unique verification ID searchable through our public COA Lookup tool, and complete analytical data packages are available on request.

Question 18

Do you test custom, modified, or non-standard peptides?

Accepted Answer

Yes. We have validated methods for cyclic, stapled, PEGylated, phosphorylated, glycosylated, lipidated, and D-amino acid peptides, as well as peptide-drug conjugates. For unusual compound classes, contact our team to scope the project — we will confirm method suitability and any development work needed before quoting. Learn about Special/Custom Testing Projects.

Question 19

How much sample do I need to send?

Accepted Answer

Most analyses require 1–5 mg of solid material or an equivalent volume of solution. Total Yeast & Mold and endotoxin testing require larger volumes (typically 5–10 mL of solution). We will confirm exact sample requirements when you submit your order, and we can work with smaller quantities for high-value or scarce compounds.

Question 20

Are your methods GLP-compliant?

Accepted Answer

Our analytical methods follow GLP principles and are aligned with ICH (Q1A, Q1B, Q3A). We are not a GMP release-testing facility — for GMP work we partner with clients to bridge research-grade characterization into their GMP supply chain.

Question 21

Can I track my order and access past CoAs?

Accepted Answer

Yes. Every submission gets a unique order ID for real-time tracking through our Track Order portal. Past CoAs are permanently archived and retrievable through COA Lookup using the verification ID printed on the report — no login required for verification.

Peptide Testing FAQs

Frequently Asked Questions around Peptide Testing

Frequently Asked Questions for Peptide Testing - Apollo Analytical specific answers!