Enhanced Diagnostic Tools
Antisense oligonucleotide is widely used in research applications as an important
tool for gene functional analysis and the development of novel therapeutic strategies.However,
one of the major obstacles for antisense therapy is efficient delivery to, and uptake
into, target cells to down-regulate gene expression. Numerous delivery vehicle
has been used to translocate oligo through target cells: oligo-liposome or using
cationic polymers such as PAMAM dendrimers, polyalkylcyanoacrylate nanoparticles,
and polyethyleneimine have been also developed for drug delivery. Numerous reports
have demonstrated by covalently attached cationic peptide CPP (cell-penetrating
peptides) or penetratin have shown promising result for enhancing delivery of antisense
to cells and tissues.
Bio-Synthesis provides high-quality and cost-effective custom oligomimetic bioconjugation
by using 2nd or 3rd nucleic acid analogs such as PNA, LNA, BNA, chimeric oligo mixed
DNA and RNA bases, 2'OMe-RNA, 2'-F-RNA and other antisense RNAs at your specific
request. Bio-Synthesis ensures that the antisense oligo bioconjugates are of highest quality
and yield. All oligo and peptide synthesis are manufacture in house and each conjugate
is meticulously monitored during synthesis and controlled according to Bio-Synthesis
stringent quality assurance and quality control standards. The final product is
identified by mass spectrum and purity is analyzed gel electrophoresis.
As one of the pioneers in providing synthetic biology tools for life science industry,
Bio-Synthesis aggressively seeks to develop new technologies to transform biology
research with novel tools.
All of Bio-Synthesis's oligomimetic antisense-peptide conjugates includes: synthesis
and modification of oligo and peptide, are carefully monitor for its sequence integrity
and systematically controlled by PAGE or mass spectrometry analysis before and after
conjugation. All conjugates are purified by HPLC, quantified by UV absorbance at
260 nm and validate by mass spectrometry and delivered lyophilized within 2-3 weeks
We also provide labeled peptide-antisense oligo conjugates and many other modifications
to meet your specific needs!
The price varies depending on different methods used in obtaining peptide-oligo conjugate. Please contact
us for a quotation.
15 % discount pricing applies to additional conjugates ordered at the same time.
Methods in preparing peptide-oligo conjugates in our laboratory are:
post-synthetic conjugation (or post-assembly conjugation, fragment coupling strategy),
total stepwise synthesis (or on-line solidphase synthesis), native ligation and
5', internal or 3'-terminus of an oligos can be covalently linked to N-, internal
or C-terminus of a peptide or other delivery vehicle such as peptide using preactivated
small molecule with functional group reside in peptide and oligo having amine, thiol,
carboxylate, hydroxyl, aldehyde and ketone, active hydrogen, alkyne/azide for cycloaddition
reactions or crosslinking with one another through variety of conjugation chemistries
that include either stable or cleavable linkage. Although, the price for using other
strategies for making peptide-oligo conjugate is the same, the price for obtaining
other modified peptides, oligo and cross linker includes either stable or cleavable
linkages, or additional spacer may be higher.
Example of using NHS ester-maleimide mediated conjugation chemistry where n-terminal
Cys incorporated peptide to react with a maleimide activated oligo. If the peptide
has an internal Cys, we can use other strategies such as oxime formation through
a hydroxyl-amine modified peptide reaction with an aldehyde modified oligo. Although,
the price for using other strategies for making peptide-oligo conjugate is the same,
the price for obtaining other modified peptides, RNA oligo, or different cross-linking
chemistries that include either stable or cleavable linkages, additional spacer
may be higher.
Product is HPLC purified and usually over 85-95% pure
Functionalization of oligo is manufactured under strict quality control process.
Analytical HPLC and MS analyses are performed in every development cycles. Depending
on type of conjugation chemistry we use, after buffer exchange (if necessary) conjugates
undergo gel gel filtration or through use of the centrifugal concentrator to remove
excess crosslinking reagents and oligonucleotides. Then by either size-exclusion
chromatography (SEC), reverse phase HPLC, may also be used to either remove excess
reagent or isolate and characterized the cross-linked product. Once the product
has been purified, it may be subject to many different types of studies including
spectroscopic (MALDI-TOF, ESI, LC-MS Fluorescence), electrophoresis.
QC (quality control) and QA (quality assurance) procedures are also followed independently
to offer you double guarantee for the highest quality possible of every delivered
conjugates. Final quantity is systematically validated by UV absorbance at 260 nm.
Moreover, our dedicated technical account managers will guide your project through
every step of the process and constantly keep you informed of the latest project
The typical delivery consists of lyophilized sample in individual fully labeled vials.
The shipment also contains COA, MS, HPLC and/or other analytical data. Additional
analytical data is also available upon request.
Contact our Technical Service Center at 800.227.0627 or contact us online
with your detailed oligo-peptide project specifications, a project manager will be
assigned to help you with design and develop an appropriate synthetic method for
your specific needs.
For us to better understand your customized project, please complete our Bioconjugation Service Questionnaire. The more our chemists understand your project needs, the more accurate feedback we will be able to provide you. Provide us with your project details will enable to us to recommend the best reagents to use for your project. The most useful and readily available tools for bioconjugation projects are cross-linking reagents. A large number of cross-linkers, also known as bifunctional reagents, have been developed. There are several ways to classify the cross-linkers, such as the type of reactive group, hydrophobicity or hydrophilicity, and the length of the spacer between reactive groups. Other factors to consider are whether the two reactive groups are the same or different (for example, heterobifunctional or homobifunctional reagents), whether the spacer is cleavable, and whether the reagents are membrane permeable or impermeable. The most accessible and abundant reactive groups in proteins are the ϵ-amino groups of lysine. Therefore, a large number of the most common cross-linkers are amino selective reagents, such as imidoesters, , sulfo-N-hydroxysuccinimide esters, and N-hydroxysuccinimide esters. Due to the high reactivity of the thiol group with N-ethylmaleimide, iodoacetate and a-halocarbonyl compounds, new cross-linkers have been developed that contain maleimide and a-carbonyl moieties. Usually, N-alkylmaleimides aremore stable than their N-aryl counterparts.
In addition to the reactive groups on the cross-linkers, a wide variety of connectors and spacer arms have also been developed. The nature and length of the spacer arm play an important role in the functionality. Longer spacer arms are generally more effective when coupling large proteins or those with sterically protected reactive side-chains. Other important considerations are the hydrophobicity, hydrophilicity, and the conformational flexibility. Long aliphatic chains generally fold on themselves when in an aqueous environment, which makes the actual distance spanned by such linker arms less than expected. Instead, spacers that contain more rigid structures (for example, aromatic groups or cycloalkanes) should be used. These structures, however, tend to be very hydrophobic which could significantly decrease the solubility of the modified molecules or even modify some of their properties. In such cases, it is recommended to choose a spacer that contains an alkylether (PEO) chain. Bio-Synthesis offers several cross-linkers with PEO chains, such as thiol-binding homobifunctional reagents, heterobifunctional based, and their derivatives.
Within 3-5 days upon receiving your project scope, we will provide you an appropriate quotation. An order can be placed with PO (Purchase Order) or major credit cards ( ). Your credit card will be billed under Bio-Synthesis, Inc.