Microparticle Nanoparticle Bioconjugation
Microparticle Nanoparticle Bioconjugation

Note: This service is currently discontinued !

Custom Nanoparticle Conjugation Services

Bio-Synthesis offers particle conjugation to be used in various biological applications. Biomolecules include antibodies, protein A, protein G, lectins, enzymes, toxins, and other proteins have all been conjugated to macroparticle or nanoparticle for diagnostic tests and numerous other research products. With the recent explosion in nanotechnology, the relevant particle size has shrunk by 2-3 orders of magnitude and the applications for particle have dramatically expanded. Nanoparticle and microparticles are used in agglutination tests and assays, particle capture ELISA methods, lateral flow tests, solid phase assays, scintillation proximity assays, polymerase chain reaction (PCR) tests, superparamagnetic-based assays and magnetic separation systems, biosensors, as enhancers of Ramam spectral signals, in light scattering assays, and as fluorescent labels or stains for detecting biological molecules.

Relying on a state-of-the art chemical biology facilities and over 30 years of combined experience in providing high quality bioconjugate complexes, Bio-Synthesis’ custom particle microsphere conjugation service is flexible, reproducible and quality guaranteed!

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 for your specific needs.

Application of Nanoparticle Conjugates

  • Agglutination Tests/Assays
  • Calibration/Validation
  • Cell Separation
  • Flow Cytometry/Fluorescence Microscopy
  • Immunochromatographic Strip Tests/Assays
  • Instrument QC
  • Magnetic Particle Assays
  • Molecular Diagnostics
  • Nucleic Acid Purification
  • Protein Purification
  • Proximity Assays

Our Benefits

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?

Particle Types

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 assays.

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 properties.

Particle Bioconjugation Portfolios

  • Agarose-DNA,
  • Agarose-Peptide
  • Oligo-qDot
  • Antibody-Luminex Bead
  • Antibody/antigen-membrane
  • DNA-Luminex Bead
  • DNA-Magnetic Beads
  • DNA-Gold nanoparticles
  • Antibody-Gold
  • 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 Bio-Synthesis.

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.