PolyPeptide Synthesis

Protein Introduction

Peptide Synthesis Introduction

Peptide synthesis service is the core service of polypeptide. In order to improve our service and product quality, we use modern precision instruments such as Waters LC-MS, Agilent HPLC etc., train our staff with professional knowledge, establish a perfect management system and advanced manufacturing process,and make the QC according to the requirements of ISO 9001 : 2008. All of these efforts make us build an example of “efficient, high quality” in the field of peptide synthesis. We encourage research and innovation and put high inputs on them.
With many years of strong peptide synthesis and research experience, we have developed highly specific expertise to synthesize various types of modified and difficult peptides. With a diverse range of modifications available for peptides, we routinely meet our clients’ specifications with unusual custom made peptides.

Range of Services：

Linear peptides: Quantity from mg to kg, up to 180 residues.

The range of purity: Crude、Desalted、＞70%、＞80%、＞90%、＞95%、＞98%、＞99%.

Peptide modifications: C-terminal modifications, N-terminal modifications, Fluorescence and Dye Labeling Peptides, Cyclic Peptides Synthesis, Phosphopeptides etc.

Peptides with different structures: Linear peptides, MAPs, Cyclic peptides etc.

Antigen peptides: KLH, BSA, 0VA coupling.

Different packages: we can make aliquots according to the demand of customers, and it’s free.

Highlight：

High quality: MS , HPLC, Certificate of Analysis and Route of Synthesis can be provided every lot of peptide order.

Fast delivery time: 2-3 weeks!

Experienced synthesis skills: up to 180 residues, more than 400 kinds of modifications including Fluorescence and Dye Labeling Peptides, Cyclic Peptides Synthesis, Phosphopeptides etc.

High Success Rate: >98%.

Confidential: Confidential aggreement can be signed!

How to place a order：

1）Contact us at: [email protected]；

2）Provide us peptides information including Sequence, Purity, Quantity and modification(If necessary, we agree to sign confidential agreement with you before you provide these information), we will make you a quotes within 30 minutes.

3）Place us a purchaser order, we can send you a sales contract too if you need.

4）Start synthesis, and we will inform you the updates of synthesis in time.

5）Arrange shippment, HPLC analysis, MS spectrum will be shipped along the peptides too.

6）Refund all pre-payment(if pre-pay us) if we failed to synthesize any of them.

7）After-sale service: Contact us anytime if you have any problem when you use the peptides, and we will reply you as soon as possible.

Small Molecules Synthesis

polypeptide.ltd has a professional team consisting of Doctors, chemists who are engaged in small molecules synthesis many years, besides, we invite experienced specialists as our senior chemical consultant to give us cutting-edge technologies on small molecules synthesis. At present, polypeptide.ltd has 400 square metres office, 1000 square meters standard laboratory. All of our laboratories are equipped with modern precise instruments from manufacture, purification, lyophilization, QC to QA including Agilent LC-MS, GC, HPLC, ultra pressure liquid chromatography, imported lyophilizer etc. And we equip our laboratories with mordern instruments for solid phase and liquid phase organic synthesis, which make us have the capacity to manufacture organic compounds from milligrams to kilograms.

After continuous development and research, polypeptide.ltd accumulated rich experience on small molecules synthesis. polypeptide.ltd can offer our customers efficient small molecules synthesis service including development, scale-up and lot production for all kinds of organic intermediates and pharmaceutical intermediates. polypeptide.ltd has built long-term cooperation with many well-known pharmaceutical factories, institutes and universities.

Reactions we’re good at:

Chiral reactions and separation, oxidation-reduction reactions, condensation, nitration, bromination etc.

High-pressure reactions(up to 60 kgs), refrigeration (till -60℃), etc.

Compounds we’re good at:

Heterocyclic compounds such as Pyridine, pyrimidine, iminazole, thiophene and their derivatives; Fine chemical intermediates and their derivatives.

Range of services:

Process Development and scale-up production: With our rich experience in customized R&D, process optimization and commercial production of advanced intermediates, we could provide expertized and customized process development and manufacturing services from grams to metric tons level.

Asymmetric synthesis: polypeptide have the capacity to provide asymmetric synthesis.

Custom made service: polypeptide provides custom small molecules synthesis services, we are committed to synthesizing small molecules you want efficiently.

Antibody Production

polypeptide.ltd provides high-quality and comprehensive custom antibody production services covering every step of monoclonal and polyclonal development.

Range of Services

Highlights

Guaranteed results: We guarantee the positive western blot result and high ELISA titer (> 64,000 for polyclonal antibody and > 128,000 for monoclonal antibody).

Customized protocols: We provide customized antibody production services accroding to the requirments.

Full service: Keep close contact and communication with you during the whole project process, and report the project progress at any time.

Differences Between Monoclonal and Polyclonal Antibodies

Monoclonal Antibodies

Polyclonal Antibodies

Advantages

· High specificity to a single epitope

· Low likelihood of cross-reactions and background noise

· Batch to batch homogeneity

· Easy to produce large quantities of identical antibody

· Higher affinity against the antigen due to recognition of multiple epitopes

· Tolerance to antigen changes

· Easy to produce with an inexpensive price and a short period of time

· Highly stable and tolerant of pH or buffer changes

Disadvantages

· Long period of time of production

· Significantly expensive

· Intolerance to changes in the antigen

· Variability between different batches

· High likelihood of cross-reactions

· Background noise

Applications

· Detection for a specific antigen

· Staining cells with less background

· Detection of the changes in molecular conformation or phosphorylation states

·Immunotherapy

· Detection for a known or unknown isoforms of antigens with high antigen homolog

· Detection for targets with possible genetic glycosylation or conformational changes

· Detection a target in solutions with varying pH and salt concentrations

In summary, monoclonal antibodies are ideal solutions for diagnostic manufacturing and therapeutic drug development that require large volumes of identical antibody against a single epitope. Polyclonal antibodies provide more advantages than that of monoclonal antibodies for general research applications.

Differences Between Species

The most commonly used hosts for antibody production are mice and rabbit, while other hosts are rat, goat and chicken. The characteristics are as follows:

Advantages		Disadvantages
mice	· Can be used to produce Monoclonal Antibodies · Short immunization cycle · Low cost
rabbit	· High success rate · larger range of antigens · Higher affinity and specificity · greater variety of epitopes
rat	· Little antigen required · Good for small amount of polyclonal antibody production · Low cost		·Small amount of serum
goat	· Good for large amount of polyclonal antibody production · Serum can be used directly in initial assays		· Large antigen quantities required · High cost
chicken	· High specificity · Moderate cost · Good alternative for highly conserved mammalian proteins		·Difficult to isolate antibodies

polypeptide.ltd have rich experience in the expression of recombinant proteins (antibodies, enzymes, membrane proteins, cytokines, etc.) in any species. We can provide protein expression and purification services from small-scale to large-scale.

Recombinant Protein Production system

We offer four systems for protein expression, which are mammalian, bacterial (E.coli), yeast and insect cells. Click on the system you are interested in to see a breakdown of the steps involved with approximate pricing.：

E.coli is the most commonly used protein expression system, for its advantages of fast growing, high protein expression level, and low cost (compared to mammalian expression system).

Mammalian cells can correctly and effectively express eukaryotic proteins, including the synthesis, processing, and secretion of proteins.

Yeast protein expression system is a ideally suitable expression system for both secretion and intracellular expression as the yeast offer relatively easy genetic manipulation and rapid growth to high cell densities on inexpensive media.

The baculovirus expression vector system (BEVS) is one of the four major expression systems of genetic engineering. BEVS has several advantages of using the baculovirus-insect cell expression system.

Comparison between different systems for protein expression

System	Bacterial	Mammalian	Yeast	Insect
Turnaround	4-6 weeks	6-9 weeks	6-9 weeks	6-9 weeks
Price	Low	Moderate	High	High
Expression Level	>50%	>10%	>20%	>30%
Protein folding	Part folding	Part folding	Correct Folding	Correct Folding
Production scale	Large	Moderate	Moderate	Moderate
Phosphorylation	No	Yes	Yes	Yes
Acetylation	No	Yes	Yes	Yes
Amidation	No	Yes	Yes	Yes
Glycosylation	No	Yes	Yes	Yes
γ-carboxylation	No	Yes	Yes	Yes