Application of Nanoparticle Conjugates
- Agglutination Tests/Assays
- Cell Separation
- Flow Cytometry/Fluorescence Microscopy
- Immunochromatographic Strip Tests/Assays
- Instrument QC
- Magnetic Particle Assays
- Molecular Diagnostics
- Nucleic Acid Purification
- Protein Purification
- Proximity Assays
The use of Bio-Synthesis's unique expertise in bioconjugation chemistries, we ensures
high quality conjugates are produced.
- High quality well-characterized conjugates
- Flexible service options
- The experience and ability of a dedicated team
- Manufacturing technology transfer
How to choose?
Fluorescent or dyed latex particles are often used in multiplexed detection system
using suspension arrays (e.g, Luminex technology). Dyed particles also are commonly
used in diagnostic lateral flow tests (like the common home pregnancy test).
Polymeric particles are monomers or copolymer in combinations. Common polymeric
particles includes: polystyrene, poly(styrene/liinylbenzene) copolymers, poly(styrene/acrylate)
copolymers, polymethylmethacrylate (PMMA) and poly(hydroxyethylmethacrylate) (pHEMA)
Micro or nanoparticle size may be critical to the proper function of an assay, or
it may be secondary to other characteristics. Considering traditional diagnostic
methods, the test or assay format commonly dictates particle size. Similar to the use of very small spheres (~0.1-0.4m) to ensure satisfactory wicking in lateral flow
tests, or the use of larger, cell-sized spheres (~4-10m) for bead-based flow cytometric
In magnetic separations, particularly those involving capture and elution of target,
the exact size of the magnetic particle may be unimportant, provided that the particles
are in some general size range, and offer desired separation characteristics
Diameter also determines surface area. Small-diameter spheres present more surface
area per unit weight, while larger spheres present more surface area per bead. Size
also affects ease of handling, processing considerations (such as the method used
for separations [centrifugation, dialysis, filtration]), and the amount of reagent
needed for coating.
Common microsphere compositions include polystyrene (PS), poly(methyl methacrylate)
(PMMA), and silica. These materials possess different physical and optical properties,
which may present advantages or limitations for different applications.
Polymer beads are generally hydrophobic, and as such, have high
protein binding abilities. However, they often require the use of some surfactant
(e.g. 0.01-0.1% Tween 20 or SDS) in the storage buffer to ensure ease of handling.
During synthesis, functional monomers may be co-polymerized with styrene or methyl
methacrylate to develop beads with surface reactive groups. Functional groups may
be used in covalent binding reactions, and also aid in stabilizing the suspension.
Silica microspheres are inherently hydrophilic and negatively charged.
Consequently, aqueous silica suspensions rarely require the use of surfactants or
other stabilizers. Carboxyl- and amine-functionalized silica spheres are available
for use in common covalent coating protocols, and plain silica microspheres may
be modified using a variety of silanes to generate functional groups or alter surface
Particle Bioconjugation Portfolios
- Antibody-Luminex Bead
- DNA-Luminex Bead
- DNA-Magnetic Beads
- DNA-Gold nanoparticles
- Lecint-Gold Conjugates
- (Strep)avidin-Gold Conjugates
- Oligonucleotide-Gold Conjugates
- Fluorescent Labeled Latex
- Polymeric Microspheres and Naosphere bioconjugation
Cant find the type of service you need? Dont worry. We have provided numerous
bioconjugation services that extend beyond the described service portfolio. Simply
contact us with your detailed project descriptions.
In most cases, we can accommodate your bioconjugation needs!
Sample Submission Requirement :
Biomolecule supplied by customers should be sufficiently pure. Please provide 3-5
mgs of starting material with the necessary data for purity assessment. Commercial
available biopolymers can be supplied by customers or synthesize or ordered through
Particle Conjugation Service Descriptions
Price: Price varies based on the project specifications. Price
does not includes cost of small molecule or biopolymer which required to be supplied
by customer or order through Bio-Synthesis from a commercial vendor. Some of the
small molecules are commercially available in an activated form.
Please contact us for a quote.
Chemistry: Coupling of preactivated small molecule and biomolecule
with chemical reactive groups such as amine, thiol, carboxylate, hydroxyl, aldehyde
and ketone, active hydrogen through use of various cross linkers.
Type of macroparticle and nanoparticle
Glass, plates, nitrocellulose membranes, polystyrene, dextran gels, resins, nanogold,
nanosphere, nanocrystal, polymer microspheres, magnetic sphere, fluorescent sphere
or luminex beads and qDot.
Ordering and Submitting Requests for Bioconjugation Services
For us to better understand your customized project, please complete our Bioconjugation Service Questionnaire. The more our chemists understand your project’s needs, the more accurate your provided feedback will be. Providing us with your project’s details enables 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 (i.e. heterobifunctional or homobifunctional reagents), spacer is cleavable and if 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 containing 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 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, making the actual distance spanned by such linker arms less than expected. Instead, spacers containing 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 alkyl ether (PEO) chain. Bio-Synthesis offers several cross-linkers with PEO chains, such as thiol-binding homobifunctional reagents, heterobifunctional bases 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.