Custom peptide synthesis for research projects ranging from standard peptide sequences to larger, modified, and technically challenging peptides.
Celtek Peptides provides custom peptide synthesis services for universities, research institutes, biotechnology companies, and pharmaceutical research teams. Each project can be configured around the peptide sequence, required quantity, target purity, modifications, and analytical requirements of the research.
Our goal is straightforward: provide researchers with clearly characterized peptide material and the documentation needed to understand what was synthesized.
For a custom project, start by sending us the peptide sequence along with the quantity and purity you need. Celtek can then review the sequence for feasibility, purification requirements, modifications, scale, and analytical testing.
Request a Custom Peptide Quote
Custom Peptide Synthesis Built Around Your Research
Not every research project needs the same peptide specification.
A preliminary experiment may require only a few milligrams of a relatively short, unmodified sequence. Another project may require higher purity, unusual amino acids, phosphorylation, biotinylation, cyclization, terminal modifications, a longer sequence, or substantially more material.
Celtek’s custom peptide synthesis services are designed around those differences rather than treating every sequence as the same project.
Current capabilities include:
- Custom peptide sequences
- Milligram-scale synthesis
- Gram-scale synthesis
- Larger-scale projects subject to review
- Target purity levels from desalted material through >98%
- Peptides up to 100 amino acids, subject to sequence feasibility
- Unusual and modified amino acids
- Phosphorylated peptides
- Biotinylated peptides
- N-terminal and C-terminal modifications
- Cyclic peptides
- Specially designed research peptides
- HPLC purification
- HPLC purity analysis
- Mass spectrometry analysis
- Additional analytical testing by request
- Lyophilized peptide delivery
Difficult sequences, unusual modifications, and larger-scale projects are reviewed individually before a final quotation is established.
Choose the Purity Your Research Requires
Higher purity is not automatically necessary for every experiment.
Additional purification requires more processing and can affect yield, project cost, and turnaround time. The appropriate specification depends on how the peptide will be used in the research and how sensitive the experiment is to peptide-related impurities.
Available target purity options include:
| Purity Option | General Consideration |
|---|---|
| Desalted | Appropriate when extensive purification is not required |
| >70% | Lower-purity material for suitable research applications |
| >80% | Often suitable for exploratory or qualitative research |
| >90% | Cleaner material for applications requiring greater selectivity |
| >95% | Higher-purity material for assays where impurities may affect results |
| >98% | High-purity projects with tighter analytical requirements |
If you are unsure which purity level to request, tell us about the intended research application when requesting a quote.
A preliminary screening experiment, for example, may not require the same purity as an assay in which relatively small amounts of peptide-related impurities could affect the measurement.
Choosing the appropriate specification rather than automatically selecting the highest available purity can make a project more practical while still meeting the needs of the research.
Peptide Quantities From Milligrams to Larger Scales
Custom peptide requirements often change as a research program develops.
An early experiment may require only a few milligrams. Once a sequence has been evaluated, the same research group may need substantially more material for expanded experiments or continued development.
Celtek supports:
Milligram-scale synthesis for smaller research projects and initial experimental work.
Gram-scale synthesis when substantially more peptide material is required.
Larger-scale synthesis for projects that move beyond routine laboratory quantities, subject to technical review and quotation.
Quantity can influence synthesis planning, purification, cost, and production strategy. If you expect a project to require larger quantities later, mention that during the initial discussion even if the first order is relatively small.
Modified and Unusual Peptides
Research peptides do not always consist solely of standard amino acids.
Modifications may be used to investigate biochemical properties, introduce an experimental label, enable conjugation, reproduce a post-translational modification, or create a different molecular structure.
Celtek’s current custom synthesis capabilities include:
- Unusual amino acids
- Phosphorylation
- Biotinylation
- N-terminal modifications
- C-terminal modifications
- Cyclization
Modified peptides are evaluated individually because synthesis difficulty can depend heavily on both the sequence and the type and location of the modification.
A modification that is relatively straightforward in one peptide may create a more difficult synthesis or purification challenge in another.
When requesting a modified peptide, provide the full sequence and clearly identify each requested modification.
Large and Technically Difficult Peptides
Peptide synthesis generally becomes more challenging as sequences become longer or chemically more complex.
Factors such as hydrophobicity, aggregation, repeated residues, difficult coupling steps, unusual amino acids, and particular sequence motifs can affect synthesis, purification, yield, and analysis.
Celtek currently accepts custom peptide projects for sequences up to 100 amino acids, subject to sequence feasibility.
Sequence review matters more than length alone. A relatively straightforward long peptide may be more practical to synthesize than a shorter sequence that is highly hydrophobic, aggregation-prone, or heavily modified.
For longer or technically difficult peptides, send us the complete sequence before ordering so the project can be evaluated before production begins.
HPLC Peptide Purification
Peptide synthesis produces the target sequence along with peptide-related byproducts that can result from incomplete reactions, deletion sequences, side reactions, and other synthesis processes.
Purification is used to separate the desired peptide from these unwanted components.
Celtek uses high-performance liquid chromatography (HPLC) for peptide purification, including reversed-phase chromatography.
The amount of purification required depends in part on the final purity specification. A desalted peptide requires substantially less purification than a peptide requested at >95% or >98% purity.
This is one reason purity can affect project complexity, yield, cost, and turnaround time.
HPLC and Mass Spectrometry Analysis
Purity and identity are related, but they are not the same measurement.
Custom peptide projects currently include HPLC analysis and mass spectrometry analysis.
HPLC is used to characterize the chromatographic purity of the final peptide.
Mass spectrometry provides evidence that the molecular mass of the material corresponds to the expected peptide.
Using both methods provides more useful analytical information than relying on a purity percentage alone. A strong HPLC purity result establishes chromatographic purity, while mass spectrometry provides an additional measurement supporting peptide identity.
Custom peptides are also supplied with a synthesis report.
Additional analytical testing may be available when required by the project. Include any special analytical requirements when requesting your quotation so they can be evaluated as part of the project specification.
Lyophilized Peptide Delivery
Custom peptides are normally supplied in lyophilized form.
The appropriate storage and handling conditions can vary from one peptide to another. Sequence, modifications, oxidation sensitivity, hygroscopicity, and other molecular properties can affect stability.
Researchers should therefore treat storage requirements as peptide-specific rather than assuming that every lyophilized peptide has identical handling requirements.
How Custom Peptide Synthesis Works
1. Send Us Your Sequence
Provide the peptide sequence, required quantity, target purity, modifications, and any special analytical requirements.
If the peptide is technically difficult or the project has unusual requirements, include as much relevant information as possible.
2. We Review the Project
Celtek reviews the sequence and requested specifications for synthesis feasibility, purification requirements, modifications, scale, and analytical needs.
Questions or potential challenges can be addressed before production begins.
3. Receive Your Custom Peptide
After synthesis and purification, the peptide is analyzed and supplied in lyophilized form with the analytical documentation included for the project.
Custom Peptide Synthesis Turnaround
Most standard custom peptide projects are currently estimated at approximately 2 to 3 weeks after an official order is received.
This is a typical project estimate rather than a guarantee for every sequence.
Factors that can extend turnaround include:
- Longer peptide sequences
- Difficult or aggregation-prone sequences
- Special modifications
- Larger quantities
- High-purity specifications
- Unusual purification requirements
- Additional analytical testing
If your research has a firm deadline, include it with the quote request so timing can be evaluated before the order is placed.
What Determines Custom Peptide Pricing?
Custom peptide synthesis is priced by project because two peptides of the same length can require very different amounts of work.
The primary factors affecting a quotation include:
Sequence length. Longer sequences generally require more synthesis steps.
Quantity. Producing a few milligrams and producing several grams require different production planning.
Purity. Higher target purity typically requires more extensive purification.
Sequence difficulty. Hydrophobic, aggregation-prone, unusual, or otherwise challenging sequences can require additional work.
Modifications. Phosphorylation, biotinylation, unusual amino acids, cyclization, and terminal modifications can change synthesis complexity.
Analytical requirements. Testing beyond the standard synthesis report, HPLC analysis, and mass spectrometry can affect the scope of the project.
For these reasons, Celtek uses project-specific quotations for custom peptide synthesis.
This allows the quotation to reflect the actual sequence, specifications, scale, and analytical requirements rather than applying the same price structure to materially different projects.
What to Include With Your Quote Request
Providing a complete specification makes it easier to evaluate the peptide correctly the first time.
Include as much of the following information as possible:
- Peptide sequence
- Desired quantity
- Required purity
- N-terminal requirements
- C-terminal requirements
- Any unusual amino acids
- Phosphorylation, biotinylation, cyclization, or other modifications
- Special analytical requirements
- Number of different peptide sequences
- Expected project timeline
- Known sequence, synthesis, or solubility concerns
If you are unsure about the appropriate purity or another specification, include the intended research application so the project can be reviewed with that context in mind.
Custom Peptides for Research Applications
Celtek has experience with the design and synthesis of peptides used across biochemical and cell-based research.
Custom projects may include peptides for areas such as:
- Enzyme research
- Antigenic peptide research
- Receptor and ligand studies
- Cell-signaling research
- Peptide transport research
- Intracellular delivery research
- Cell-penetrating peptide research
- Biochemical assay development
Celtek’s scientific history includes research involving cell-penetrating peptides, intracellular delivery, and peptide technologies designed to influence signaling pathways.
Custom peptide synthesis services are provided for legitimate laboratory research and development applications.
Why Sequence Review Matters
A custom peptide project involves more than a sequence and a requested quantity.
The peptide sequence itself can influence:
- Synthesis difficulty
- Expected yield
- Purification
- Solubility
- Stability
- Modification strategy
- Analytical interpretation
For technically challenging projects, reviewing the sequence before production can identify potential issues before significant synthesis work begins.
This is especially important for longer peptides, hydrophobic sequences, heavily modified peptides, unusual amino acids, and larger-scale projects.
Frequently Asked Questions
What purity levels are available for custom peptides?
Current target purity options include desalted material and >70%, >80%, >90%, >95%, and >98% purity. The appropriate specification depends on the needs of the research.
How are custom peptides analyzed?
Custom peptide projects currently include a synthesis report, HPLC analysis, and mass spectrometry analysis. HPLC characterizes chromatographic purity, while mass spectrometry provides supporting evidence of peptide identity based on molecular mass.
Can Celtek synthesize modified peptides?
Yes. Current capabilities include unusual amino acids, phosphorylation, biotinylation, terminal modifications, and cyclization. Technically complex modifications should be reviewed individually with the complete peptide sequence.
How long can a custom peptide be?
Celtek currently accepts peptide synthesis projects for sequences up to 100 amino acids, subject to sequence feasibility. Length alone does not determine difficulty, so longer and technically challenging peptides should be evaluated before an order is finalized.
What quantities are available?
Custom synthesis is available for milligram and gram quantities. Larger-scale projects can also be reviewed and quoted individually.
How long does custom peptide synthesis take?
Most standard projects are currently estimated at approximately 2 to 3 weeks after an official order is received. Difficult sequences, modifications, larger quantities, high-purity specifications, and additional analytical requirements can increase turnaround time.
How much does custom peptide synthesis cost?
Pricing depends on the sequence, quantity, purity, synthesis difficulty, modifications, scale, and analytical requirements. Celtek provides project-specific quotations so pricing reflects the actual requirements of the peptide.
Are custom peptides supplied lyophilized?
Yes. Custom peptides are normally supplied in lyophilized form. Storage and handling requirements should be evaluated for the specific peptide.
Request a Custom Peptide Synthesis Quote
Send Celtek your peptide sequence along with the required quantity, target purity, modifications, and any special analytical requirements.
For unusual, modified, longer, or technically difficult peptides, include as much relevant project information as possible. Celtek can review the sequence before establishing the final specification, expected timeline, and quotation.
Request a Custom Peptide Quote
For Research Use Only. Not for human or veterinary use. Not for diagnostic or therapeutic use.