GenScript has been providing reliable custom peptide synthesis services for 10,000+ scientists worldwide for 18+ years. With our proprietary microwave-assisted PepPower™ peptide synthesis platform, GenScript is now able to offer high-quality peptides with 100% guaranteed quantity at industry-leading speed, as fast as 5 days, to help expedite your research. Also for a limited time we are offering a purity upgrade from lower to higher at no extra charge to help you obtain better results while saving you money.

>98% Success Rate icon >98% Success Rate
leading speed icon Industry-leading speed:
As fast as 5 BDs
 18+ Years  Peptide Synthesis Experience 18+ Years
Peptide Synthesis Experience
mg to kg mg to kg
Crude to >98%
<200 AA icon <200 AA
300+ modification icon 300+ modification

Package Options Custom Peptide Synthesis

Fast Peptide Synthesis 3 Rush Peptide Synthesis 3 Regular Peptide Synthesis 3
Starting turnaround time 1
(Business Days)
6 5 10
Sequence length Up to 25 AA <200 AA
Purity Free Upgrade! ≥70% to ≥98% Crude Crude to ≥98%
Guaranteed Quantity 2 Up to 100 mg mg to kg
Solubility Test Service Free
TFA Exchange Service Standard Service Standard & Guaranteed Service
Modifications 30+ modifications
List of modifications for fast and rush services
300+ modifications
List of modifications for custom peptide synthesis service

1.Turnaround time includes all business days from order confirmation to completion, not including shipping time.
2.Guaranteed quantity is valid for Regular and Express Peptide Synthesis Services on orders with less than 20 mg in quantity.
3.Custom Peptide service includes Regular and Express Peptide services. Express Peptide Synthesis Service includes Fast and Rush Peptide Synthesis Services. Express peptide synthesis service is limited for non-complex sequences and modifications, please contact us or request a quote.

Peptide Library

Crude Peptide Library Upgraded! Purified
Peptide Library
Crude Micro-scale
Peptide Library
Purified Micro-scale
Peptide Library
Turnaround Time 1
(Business Days)
9 - 17 15 - 20 15 - 20 15 - 20
Sequence Length 5 - 15 AA 16 - 25 AA 5 - 25 AA 5 - 20 AA
Purity Crude ≥70% to ≥98% Crude >70%
Quantity 1 – 20 mg 1 – 9 mg 0.2 - 0.5 mg
Minimum order size 24 peptides
Deliverable format 2 Lyophilized peptides in individual vials Free
or 96-well plate Charged
Lyophilized or liquid (suspended in 50% (v/v) acetonitrile/water containing 0.05% TFA) in Thermo Scientific Matrix 96-tube plates
Quality documents 3 COA & MS only
COA, HPLC & MS for each peptide
COA, HPLC & MS for each peptide COA, HPLC & MS for each peptide
Modifications Biotin, Fluorescent Dyes, Phosphorylation, Methylation, Acetylation, Amidation, Head to Tail Cyclic, Disulfide Bridge, Stable Isotope Labeled Amino Acids, Unnatural Amino Acids, etc. Amidation, Acetylation, Biotin, FITC-Ahx, Isotope Labeling on K/R, Arg (13C6, 15N4), Lys (13C6, 15N2) and many more

1.Turnaround time includes all business days from order confirmation to completion, not including shipping time.
2.Automated peptide pooling available upon request.
3.Additional services (TFA exchange, analytical HPLC, etc.) are available at additional cost.

The GenScript Edge

icon Standard Peptide Library Peptide Library Service

Large variety of peptides for target screening, immunotherapy, vaccine development, drug discovery and proteomics.

Learn More
icon Neoantigen Peptide Service NeoAntigen Peptide Service

From functional screening of neoantigen candidates for TCR therapy to clinical stage vaccine immunogenicity testing.

Learn More
icon Large-Scale Peptide Synthesis Large Scale Peptide Synthesis Service

Perfect for peptide drug & Active Pharmaceutical Ingredient (API), cosmetic peptides, and feed additive development.

Learn More


Delivery Specifications


Your peptides will arrive as lyophilized powder with following features:

HPLC and MS Reports for Each Peptide

ArgonShield Packaging

Certificate of Analysis: The appearance, quantity, molecular weight and purity of each peptide will be analyzed and included in the Certificate of Analysis report.

Premium Services

AccuPep+ QC services >>
Our AccuPep+ QC services that can help you assess peptide sample consistency and obtain reproducible results.
Solubility Testing Service >>
Dissolve peptide with up to 3 testing solvents to achieve the maximum concentration by saving your peptide sample.
TFA Exchange Services >>
Reduce TFA content to be <1% to help avoid the impact of TFA on your research.
Endotoxin Control and Analysis Services >>
GenScript offers Endotoxin Control and Analysis services to reduce endotoxin content to be ≤0.01 EU/µg.

Tools & Resources


  • General

  • Peptide Synthesis step

  • What is the maximum peptide length you can produce?

    We had produced the peptides containing 200 residues. However, peptides longer than 100a.a are extremely difficult to synthesize. We can evalute them case by case and try our best to make them by fragmentation and ligation.

  • What will be the maximum number of consecutive Pro peptide you can make?

    We had produced peptides containing 16 consecutive Pro residues. If you'd like to, we can have a try, but it is hard to ensure success.

  • Can you make peptides with "Q" at the peptide N terminus?

    For the sequence with "Q" at the N terminus, it is important to note that this configuration is not stable and may undergo a cyclization reaction to form pGlu. While obtaining a qualified peptide with this sequence can be challenging, we are willing to make an attempt if you are interested. However, if the peptide is urgently needed for your project, you may consider the following options to prevent such cyclization:
    Removing "Q" from the N-terminus
    Adding another amino acid in front of "Q"
    Applying N-terminus acetylation.

  • Why would I want to do TFA exchange for my peptides?

    In chemical terms, a counterion is an ion of opposite charge to another ion in a solution or an electrochemical system. In peptide synthesis, counterions such as TFA are used for cleavege and HPLC separation, and TFA counterions binds to the basic amino acids or N-termini, so synthetic peptides are usually obtained as TFA salts. In some cases, TFA counterions may be harmful to biological assays (see Top 5 reasons peptide assays fail), however GenScript can replace TFA counterions with acetate or HCl, upon requesting our TFA removal service.

  • What is net peptide content?

    It is important to understand the difference between net peptide content and total peptide content. The dry peptide powder shipped to you usually contains not only peptides, but also some other substances such as water, absorbed solvents, counterions, and salts. The total peptide content(gross weight) refers to the weight of this mixture. Net peptide weight indicates the actual weight of the peptide component of your sample. Net peptide content is usually 50-80% of the total peptide weight (also called gross peptide weight) and is usually determined by amino acid analysis or Nitrogen analysis. Net peptide content should not be confused with purity. Purity defines the percentage of the target peptide sequence in the peptide component of your sample.

  • How do you calculate theoretical net peptide content?

    Theoretical net peptide content (calculated assuming that counterions are the only non-peptide components present in your peptide sample) can be estimated by dividing molecular weight of the peptide by a sum of this molecular weight and a number of trifluoroacetate counterions that are required to neutralize the peptide multiplied by the molecular weight of the TFA counterion (MW= 114). For example, a synthetic peptide of MW=1000 with a free N-terminal amino group and one Arg has theoretical net peptide content of 1000/(1000 + 2 x 114 ) = 1000/1228 =0.81 or 81%. In practice, counterions are not the only possible non-peptide impuritiies in the peptide sample. It can also contain water, absorbed solvents and traces of other substances. As a result, the actual net peptide content is usually determined by quantitative amino acid analysis.

  • Why are highly hydrophobic peptides difficult to be produced?

    Highly hydrophobic peptides are prone to aggregate, which increases the difficulty of synthesis. Highly hydrophobic peptides are easy to adhere to the column, which increases the difficulty of purification.

  • What is the purity of "crude"?

    For the purity that is less than 70%, GenScript would set it as crude.

  • What purity does my peptide need to be?

    An appropriate peptide purity is a critical factor for the success of a scientific experiment. In general, the higher the peptide purity level, the more favorable the experimental outcome. Impurities in lower purity peptides may result in toxicity or unwanted side reactions, especially for some applications such as animal studies where exceedingly pure peptides (>98% purity) are required. More details can be found at this link: https://www.genscript.com/peptide-purity.html

  • What are the reagents in the peptide sample before lyophilization?

    In general, GenScript will lyophilize the target fraction in purification directly, the main reagents are the ultrapure water, acetonitrile and TFA in mobile phases.

  • What is the delivery form of the GenScript's peptide?

    Peptides are delivered in lyophilized powder form by default, aliquoted in individual sample tubes. Meanwhile, peptides can be delivered according to customer’s requirements.

  • What information does the sample tube label contain?

    A regular peptide label contains peptide name, peptide service type, quantity, purity and Lot number. If extra information is needed, such as sequence or molecular weight, please kindly add this request when making the quote, GenScript can provide a customized label.

  • Why does the amount of peptide look different from that of the same quantity of other peptides?

    In general, the appearance of a peptide is closely related to the peptide sequence itself, it is not recommended to do comparison between different peptides. Besides, peptides delivered as white lyophilized (freeze-dried) powder can differ in visual appearance between peptides due to the retention of different compositions in the final sample. For example, the freezing cycle can contribute to visual differences depending on the rate; a slower rate will compact the peptide into a dense form. During the drying process, more water may evaporate, leaving very little peptide visible to the naked eye. The pressure applied in the process will differ from lot to lot as well. These possible scenarios may change the appearance of peptide sample in the vial but do not change the amount of peptide contained in the vial, which is weighed via analytical balance.

  • What is the reason the peptide is invisible in the vials?

    The delivered peptides are accurately weighed and aliquoted, if the peptides are invisible, there are several reasons for your reference:

    1. The peptide amount is too small to be visible using naked eye. It is recommended to dissolve the peptide in the vials provided by GenScript, then perform the experiments directly.

    2. Peptides might be adhered to the vial wall or cap, it is recommended to perform centrifugal or shake operation before your experiments.

    3. Hydrophilic sequences absorbed water during the transit or storage, it is recommended to re-lyophilize the peptides before experiments.

  • What is the shipment temperature of GenScript’s peptides?

    There are three common shipment temperatures: room temperature, blue ice (approximately 4 degrees) and dry ice (approximately -80 degrees).

    Without specific requests, peptides in lyophilized powder format will be sent out at room temperature, and peptides in liquid format will be sent out with dry ice.

    If there are special requests, please kindly add the note when preparing the quote or let GenScript know.

  • How to improve the hydrophilicity of peptides?

    Adding PEG or several Lys (3~4) in the sequence may improve the hydrophilicity of the peptides.


PACT Pharma Inc. Robert Bao, Principal Investigator

PACT Pharma Inc., USA

GenScript peptide synthesis gives us amazingly fast turnaround time and very competitive prices. Their peptide quality has been excellent. Our experience with them has been so positive that we have essentially shut down our internal peptide synthesis efforts and now use them for all of our custom peptides.

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