Reverse phase HPLC purification
HPLC purification options include guaranteed purities >70%, >80%, >95% and a unique ultra-pure >99% grade for demanding experiments.

Purification is performed by preparative or semi-preparative reversed-phase HPLC. We typically use C8 or C18 columns with linear gradients of acetonitrile in 0.1% aqueous tfa with UV monitoring at 220 nm.

HPLC elution may be monitored with UV detector set at longer wavelength for peptides containing aromatic amino acids.

The crude peptide synthesis contains by-products resulting from failed coupling cycles (i.e. truncated chains), and further oxidation, modification, or hydrolysis of side chains arising during cleavage and deprotection. The extent of impurities depends upon peptide length and primary sequence. Depending upon your specific application we would recommend purification levels along the following guidelines.
 Purity >70%: Polyclonal antibodies production; preliminary library screenings; higher levels should be considered for peptides > 20aa.
 Purity >80%: Polyclonal antibodies production with long peptides or mono-specific antibodies; affinity column making; qualitative immunoassays (ELISA, competition, depletion…); qualitative biochemical assays (enzyme activity, specificity…).
 Purity >95%: quantitative immunoassays (ELISA, competition, depletion…); quantitative biochemical assays (enzyme activity, kinetics…); generally recommended with modified peptides; structural studies (Crystal, NMR,…).
 Purity >99%, ultra-pure: cell culture assays; quantitative bioassays.

Quality control
We recognize that quality and reliability are central to our customers. As a result no peptide leaves our laboratories unless it has fully complied with our stringent QC standards.

Fast reliable peptide delivery
All our peptides are weighted and supplied as a stable lyophilized powder with comprehensive documentation. Synthesis report includes analytical HPLC trace verifying purity and a mass spectrum ensuring integrity of the desired full-length peptide. Dispatch time will vary with length, scale, purity, and modifications ordered. Our average turn around is shown in the table below, for standard synthesis scales and purities. Our customers are well advised when synthesis difficulties are encountered and product is delayed.

Long chain peptides
We routinely prepare long (30-50 aa) to very long peptides up to a maximum length of approximately 100 aa. Because overall yield decreases exponentially with increasing length, synthesis and downstream processing times may increase significantly for longer sequences.

Many peptides of length over 40 aa have raised important research interest and their syntheses remains challenging. We have been manufacturing peptides > 40 aa with consistent high potency biological activity for many years.

It has also proven to yield peptides with high activity in sensitive biochemical assays. Another noteworthy feature is a considerably increased stability of the peptides in aqueous solutions.

Peptide ends
Our peptides are normally synthesized with unblocked termini i.e. amine and carboxylic acid groups.
However in some instances, one might consider using blocking moieties, or modified ends.
N-acetyl and C-amide closely mimic internal sequences as they have uncharged ends. In addition, these blocking groups improve resistance to enzymatic degradation.

Many modifications available
Genosphere Biotechnologies provides a wide range of established peptide modification as detailed below.

A peptide is usually too small to elicit a satisfactory immune response in animals. In order to improve immunogenicity, one needs to attach the target peptide to a larger macromolecular structure. While protein carrier conjugation remains the preferred approach, the MAP (multiple antigen peptide) is used in some instances.

Protein carrier conjugation for immunization
Peptide epitopes are covalently conjugated to a larger carrier protein and the latter conjugate is used as immunogen to generate antisera.
Standard carrier is (Keyhole Limpet Hemocyanin-KLH), however other proteins are available for conjugation (Bovine Serum Albumin- BSA, Ovalbumin-OVA, etc.).
Deliverables: 5 to 10 mg of free peptide with requested purity level and 10-15 mg of peptide conjugate.

Multiple antigen peptides
Multiple antigen peptides (MAP) immunogens contains 8 copies (or 16 copies) of the peptide, synthesized directly on an 8-armed (or 16-armed) branched lysine core. The resulting multimeric is a large macromolecule (10-15 kDa) which has a high molar ratio of peptide antigen to core molecule and does not require further conjugation to a carrier protein. We typically prepare 10-20 mg of these peptides. Please note that MAP should not be used when the peptide sequence is derived from the C-terminus of the target protein.

We offer custom peptide librairies synthesis in 96-wells microplate formats. Whether you intend to screen peptides for enzyme substrate profiling, elucidate substrate specificities, protein-protein interaction region mapping, antibody epitope mapping, we provide cost-effective fmoc-based simultaneous multi-peptide synthesis technologiesto fit your needs.

Specifications
Peptide length : 5-18 aa
Free C-& N- termini unbound peptides
Amount: 1 mg (depends on sequence)
Purity: Screening / Crude grade (average purity 12mer>70%)
Analysis: Mass spectrum for every peptide
Turnaround: average 2-3 weeks

Pricing and quotation
All sequences are subject to technical evaluation and are quoted individually.
You may use our Online Quotation Form
Or if you wish to e-mail or fax, please indicate sequences (N to C terminus), mg amount, purity level, and modifications required.

Product delivery
All peptides are lyophilized, weighted and shipped by express courier at RT with a complete synthesis report that includes, an analytical reversed-phase HPLC trace (UV detection at 220 nm).

Ordering
An Online Order Form is available for your convenience. You may order by fax or e-mail as well.
For administrative purposes, we do require a copy (EMAIL/PDF, FAX or POST) of your institutional purchase order in all cases. Please write sequences N to C termini and kindly use one-letter code designation of amino acids for quotation requests and orders.