Peptide Level Determination
Accurate, reproducible peptide quantification for research, diagnostics, and therapeutics.
The weight on a peptide vial is not the weight of peptide in it. A lyophilized peptide also contains water, residual salts, and counter-ions — often 10–40% of the gross mass. Veya Peptide determines the true net peptide content by quantitative amino acid analysis (AAA) so your concentrations are correct.
Getting content wrong quietly corrupts every downstream number: dosing, IC50, and specific activity all shift by the same percentage — and the error is invisible in the final data. Peptide-content determination removes that hidden bias.
Why Peptide Content Matters
"Net peptide content" is the percentage of the powder that is actually peptide. The remainder is bound water, TFA/acetate counter-ions, and residual salts from purification.
- Accurate concentration — weigh-and-dissolve without content data can overstate concentration by 10–40%.
- Reproducibility — normalizing to net peptide makes results comparable across lots and labs.
- Quantitative assays — essential for IC50/EC50, Kd, and any dose-response measurement.
Amino Acid Analysis Method
AAA hydrolyzes the peptide to free amino acids, quantifies them against calibrated standards, and back-calculates the moles of peptide — the reference method for peptide quantitation.
- Acid hydrolysis — complete breakdown to constituent residues under controlled conditions.
- Quantitation — residue molar ratios confirm composition and yield net peptide content.
- Report — net peptide %, composition table, and calculated content per vial.
Quantified & AQUA Standards
For mass-spectrometry workflows we supply absolutely-quantified peptides so you can anchor label-free or targeted assays to a known amount.
- AQUA-style standards — amino-acid-analysis-quantified peptides for absolute quantitation.
- Mass balance — cross-checked content for internal-standard accuracy.
Service Specifications
| Parameter | Specification |
|---|---|
| Method | Quantitative amino acid analysis (AAA) |
| Reports | Net peptide content (%) + composition |
| Use cases | Concentration accuracy · quantitative assays |
| Standards | AQUA-style absolutely-quantified peptides |
| Pairs with | Custom synthesis · stable-isotope labeling |
| Deliverable | Content report + calculated µg peptide/vial |
Frequently Asked Questions
Isn't the vial weight enough?
No. Gross weight includes water, salts, and counter-ions. Only net peptide content tells you how much peptide you actually have, which is what your concentrations depend on.
How much can content vary?
Net peptide content commonly ranges from about 60% to 90% of gross weight depending on sequence, purification, and counter-ion — enough to meaningfully shift quantitative results.
Can you quantify a peptide I bought elsewhere?
Yes. We can determine net peptide content on peptides from any source so your dosing and assays are anchored to a real number.
Request Content Determination
Send us your peptide and we will return net peptide content and a full composition report so your concentrations are right. Contact our team to arrange analysis.