Labels, tags and probes that contain small compound such as florescence, visible chromogenic character can be used to label proteins and nucleic acids. Bio-affinity towards other molecules (biotin, digoxygenin), enzymatic (AP, HRP) or chemiluminescent (esters or acridine) can be used as well. Bio-Synthesis's unique and unrivalled expertise in research and development offers you the best quality fluorescent probes and is capable of providing you with multiple labels within the same molecule. Each labeled
probe service is meticulously monitored according to Bio-Synthesis's stringent
quality assurance and quality control standards for an optimized label to biomolecule
Bio-Synthesis's Custom Reporter Molecule Labeling Services includes experimental
design and development of protocols and procedure for the preparation of conjugates
to be used in various detection and assay system. For the last two decades, we have
accumulate a portfolio of reporter conjugates. To obtain further information regarding
custom bioconjugation, contact our Technical Service Center at 800.220.0627 or contact
us online with your detail project specifications. A project manager will
be assigned to help you with design and develop an appropriate synthetic method
There are many ways to label biopolymers. The choice is determined by the technique
you are going to use in your experiment. Detection of probes or labels usually takes
one of three general forms: spectrophotometric, radiosensitive detectors, or indirectly
through another labeled substance. Spectral probes can be of two types, chromogenic
or fluorescent. Chromogenic label typically are reserved for non-covalent staining
of gross structural features within cells and tissues, as these are present at relatively
high concentration. The sensitivity of visible wavelength dye often is not good
enough to provide detectability for low-concentration antigens or low-copy proteins.
Even if a protein is covalently modified with a chromogen, the number of associated
dye molecule needed to detect it just through its absorbance properties could be
prohibitively large to make it visible
Fluorescent molecules, by contrast, can provide tremendous sensitivity due to their
property of discrete emission of light upon excitation. Protein, nucleic acids,
and other molecules can be labeled with fluorescent probes to provide highly receptive
reagents for numerous in vitro assay procedures. For instance, fluorescently tagged
antibodies can be used to probe cells and tissue s for the presence of particular
antigens, and detected through the use of fluorescence microscopy techniques. Since
each probe has its own fluorescence emission character, more than one labeled molecule-
each tagged with a different fluorophore can be used at the same time to detect
two or more target molecules.
Fluorescent labeling is the process of covalently attaching a fluorophore to another
molecule, such as a protein or nucleic acid. This is generally accomplished using
a reactive derivative of the fluorophore that selectively binds to a functional
group present in the target molecule. The most commonly labeled molecules are antibodies,
which are then used as specific probes for the detection of a particular target.
Fluorescent labeling can be applied to a wide variety of detection systems and allows
sensitive and quantitative measurement.
Whether you are labeling proteins and antibodies for immunofluorescence, nucleic
acids for in situ hybridization, or lipids for membrane studies, Bio-Synthesis will
help you find the right conjugation product.
Sample Submission Requirement:
Biomolecule supplied by customers should be sufficiently pure. Please provide 1-3
mgs of starting material with the necessary data for purity assessment. Commercially available biopolymers can be supplied by customers or synthesized and ordered through Bio-Synthesis.
Price varies based on the project specifications. Our service includes materials
and labor for conjugation only! Price does not include the cost of biopolymer synthesis
or order through Bio-Synthesis from a commercial vendors and, if deemed necessary,
biopolymer modification to introduce additional functional groups, extra linkers,
spacers. Please contact us for a quote.
Discount: 15 % discount pricing applies to additional conjugates
ordered at the same time.
Coupling of preactivated label and biomolecule with chemical reactive groups such
as amine, acid, aldehyde, hydrazine, hydroxyamine, maleimide/alkyl halide, and sulfhydryl
Service Specification: Our reporter labeling services are prepared by techniques
that can allow site specific conjugation. Labeling ratio can be optimized at client's
request. After standard desalting, or purification, a small percent of heterogeneous
products containing single or multi-site conjugate per molecule may exist.
Biomolecule we use to label with various dyes, tags or probes are:
Procedure: After labeling, final conjugates must first be isolated
from excess or unreacted reagent by gel filtration or dialysis. In many cases, simple
dialysis may suffice to remove unreacted reagent from the reaction solution. Final
concentration and labeling ratio determination (if applicable).
Optional services such as gel filtration chromatography may also be used to either
remove excess reagent or isolate and characterized the cross-linked product. With
exception of dialysis, if the protein/antibody is significantly larger (>3-fold)
than the modifying or coupling reagent. For reagents (mostly protein and other biological
molecules) that are similar in size or larger than the antibody, one must resort
to other purification techniques such as affinity chromatography, ion-exchange chromatography,
and hydrophobic interaction chromatography.
Cross-linked target molecule may then be further characterized by biochemical or
biophysical techniques. 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, immunochemical biochemical, enzymatical analysis. 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.
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
Visit our literature vaults for more references and citings.
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. Providing us with your project details will enable us to recommend the best reagents to use for your own 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 are more 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 of the spacer arm, and also the length, 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.
Once the project scope has collected, we will provide an appropriate quotation within 3-5 days. Orders can be placed with either a PO (Purchase Order) or credit card. We accept POs and major credit cards ( ). Your credit card will be billed under 'Bio-Synthesis, Inc.' Click here to download our credit reference form. For international orders, we must apply the full charge at the time of the order is placed. In the unlikely event that any given order cannot be filled, our guarantee will take the form of a full refund.