Deliverables
Your peptides will arrive as lyophilized powder aliquoted into # of vials requested, along with the following features:
- HPLC and MS Reports for Each Peptide
Our ISO 9001:2008 certified, Total Quality Management (TQM) platform ensures that each custom peptide is triple checked via both electrospray ionization mass spectrometry (ESI-MS) and reversed-phase high performance liquid chromatography (RP-HPLC) analyses at each stage of the purification process for maximum peptide fidelity.
- ArgonShield™ Packaging
We package all peptides in sealed, argon gas-filled vials to prevent any oxidation and deliquescence during delivery.
- Flexible Aliquoting Options
We provide aliquoting services (free for the first 5 vials and as little as 0.2 mg/vial ) for all peptide orders, which help prevent unnecessary freeze-thaw cycles, water absorption and loss of reagent from self allocating.
- Certificate of Analysis
The appearance, quantity, molecular weight, and purity of each peptide will be analyzed and included in the certificate of analysis report. All reports can be downloaded by visiting My Account page.
Premium Services
Select our AccuPep+ QC services that can help you assess peptide sample consistency and obtain reproducible results.
Performing experiments with hydrophobic peptides can be extremely frustrating if you are unsure of how to properly dissolve your peptide. In addition, determining the optimal conditions for dissolution can consume up to 5 mg of your peptide stock. Our solubility testing service will help you conserve time, money, and peptide stock, by providing the optimal peptide dissolution condition that suits your assay requirements.
More about Solubility Testing for Peptides
Our peptide synthesis experts perform a systematic dissolution of your peptide in various buffers at varying pH to determine the conditions under which the highest concentration of dissolved peptide can be obtained.
- Your peptide sequence's characteristics are evaluated, and a customized solubility testing approach is designed.
- Your peptide is dissolved systematically in lab solvents that are most likely to yield the highest gross peptide concentration.
- You will received a customized solubility test report containing the concentration of your peptide in each of the tested solvents.
- You can view your solubility test results any time by logging into your Account page.
Trifluoroacetic acid (TFA) is a strong acid commonly used to cleave synthesized peptides from solid-phase resins and improve HPLC performance during peptide purification. Most custom peptides are delivered as lyophilized TFA salts, containing as much as 10-45% TFA. Residual TFA in peptide samples can cause cytotoxicity in cell culture assays, therefore TFA removal service is recommended for peptides that will be used in cellular assays. We provide both standard and guaranteed (TFA < 1%) TFA removal service to meet your specific research needs.
More about TFA Removal for Peptides
TFA Removal Service removes the residual TFA and replaces it with your choice of acetate or hydrochloride, both of which are more amenable for cell-based assays. Additional QC reports are provided for peptides for which this service is performed.
Deliverables:
- Peptide having desired purity and quantity, and having < 1% TFA (exchange by HCl, formate or acetate)
- TFA content test report
The delivery time is typically 2 weeks in addition to peptide synthesis time depending on peptide sequence.
Custom peptides are delivered as a gross peptide consisting of a mixture of the target peptide, peptidic impurities, counter ions, and water. Request peptide content analysis to determine the precise amount of target peptide in the gross peptide preparation and increase your experimental accuracy.
More about Peptide Content Analysis
Peptide content analysis involves quantification of the elemental nitrogen in the gross peptide preparation, which is used to calculate the amount of target peptide in the preparation via molar ratios.
Depending on the hygroscopic nature of peptides, peptide samples contain varying amount of water even after lyophilization. Water percentage contributes to gross peptide weight and may vary from batch to batch. Request this test to ensure precise dilution of your peptide samples and limit batch to batch variability for the same peptide.
More about Moisture Content Analysis
For the moisture content analysis, the water content is determined by the Karl Fischer Titration method.
Endotoxins (lipopolysaccharides), the major components of gram-negative bacteria cell wall, can be introduced into peptide samples during peptide synthesis. Even at low concentrations, endotoxins can decrease cell viability and induce immune response in cellular assays. Request this analysis when using peptides in cells that could be sensitive to endotoxins or prone to immune response.
More about Endotoxin Analysis
The endotoxin analysis utilizes the reproducible clotting of Tachypleusamebocyte lysate or Limulus amebocyte lysate in the presence of endotoxins allow for endotoxin detection as low as 0.001 EU/mL.
Request amino acid analysis to determine the amino acid composition in the peptide or determine the precise amount of the net peptide to ensure experimental accuracy and reproducibility.
More about Amino Acid Analysis
For this analysis, peptide is hydrolyzed under acid conditions into free, individual amino acid residues. Following derivation, reversed-phase liquid chromatography is used to separate the amino acid derivatives, followed by UV-detection and quantification.
Peptides preparations consist of not only the target peptide, but also other impurities, including peptidic impurities, counter-ion, and water. Request this test to characterize the impurities in your peptide sample to ensure experimental consistency.
For peptides containing fluorescence adsorptions groups (e.g. FITC, AMC, FAM, DABCYL, TMR, etc.), HPLC-UV-fluorescence detection will provide more sensitive and specific signals to help accurately assess the purity and concentration of your peptides.
Acids (e.g. TFA) used during peptide synthesis can form salts with amino groups on side chains or the amino terminus of your peptide, leading to acidity. Low pH can interfere with assay results. Request this test to ensure that your peptide preparation has your desired pH value.
More about pH Test
For pH test, peptide is dissolved in water (additional solvents may be added in case of hydrophobic custom peptides) and a pH meter is used to determine the pH value of the peptide.