A Critical Raw Material for the Manufacture of IVD and Life Sciences Reagents

Assay development continues to challenge the IVD industry, which must 

bring accurate, reliable, robust, and cost-effective assays from the conceptual phase to the end. The use of magnetic microspheres and polymer beads as the solid phase in automated immunoassays—resulting in automation, faster reactions, increased sensitivity, and shorter time per assay—has been one of the biggest technological advances. The technical capability to develop and produce, on an industrial scale, one bead or one microsphere for one application could explain, at least in part, the increasing demand in the field of microsphere technology. For instance, our production capabilities allow us to produce batches larger than 6 kg for some of our magnetic microspheres used in immunoassays, and up to 12 kg for polymer beads used in immunoturbidimetric assays or latex agglutination on slides.

To produce efficient and reproducible immobilization of immunoglobulin or other ligands, such as proteins, lipids, or polysaccharides, we offer the choice of working on many different surfaces—hydrophobic or hydrophilic, carboxyl-modified, amino-modified, or thiol-modified. Different surface chemistries, of course, should be considered and evaluated in preliminary screening protocols. However, the solid phase is, without a doubt, a critical and important part of the assay.

White Microspheres

Dyed Microspheres

Fluorescent Microspheres

Super-Paramagnetic Microspheres

Magnetic Silica Microspheres

White Microspheres

Calibration standards (NIST)

This range of our Calibrated Standards Microspheres is used in scientific and industrial laboratories for the calibration and the standardization of particle measurement systems. They also can be used in quality control programs and development of new analytical methods in numerous fields.

Principle of measurement:

First CS sample and Standard Reference Material 1690 or 1691 (NNBS) are mixed together. Then, this preparation observed by Transmision Electron Microscope (TEM) and photo are taken.

These CS Microspheres have been themselves calibrated according to the recommendations of The National Institute of Standard and Technology (NIST). The average mean microsphere diameter was determined by using TEM (Transmission Electron Microspcopy).

In a first step, the size is optically determined on a TEM microphotography. Then, the real size is obtained by multiplying this value with the effective magnification rate of the microscope when taking the photo.

Our Calibration Standard Microspheres are supplied at 0.5% concentration in water (50mg/10ml).

Our Calibration Standard Microspheres are supplied at 0.5% concentration in water (50mg/10ml).

Standard Microspheres

Our standard polystyrene microspheres are extremely uniform with an excellent lot-to-lot reproducibility. Those microspheres are mainly devoted to hydrophobic or passive immobilization of molecules (polyclonal or monoclonal antibodies, proteins, haptens etc…) onto their surface.We offer a large range of size (from 15 nanometers to 6 microns and more), making this range suitable for most Microspheres-based technologies.

• Immuno-Turbidimetric
• Nephelemetric Assays
• Enhanced Immuno-Turbidimetric Assays
• Latex Agglutination Test "LAT"
• Solid phase ImmunoAssays
• Microspheres capture ELISA
• Calibration

Very small Plain Polystyrene Microspheres

Standard Planin Polystyrene Microsphere

Large Plain Polystyrene Microspheres

Functionalized Microspheres

Our functionalized polystyrene microspheres are extremely uniform with an excellent lot-to-lot reproducibility. The introduction of highly polar or ionisable chemical groups increases the colloidal stability of the suspension and also allows the covalent binding of polyclonal or monoclonal antibodies, proteins and haptens.

The different groups -COOH, -NH 2 , -OH, -CONH 2 , -SO 3 H, -COOCH 3 are produced by copolymerisation of the corresponding functional monomers. Due to their more hydrophilic surface, our functionalized polymer microspheres have a very low grade of non-specific-binding.

The most popular protocols for covalent binding have been carried out with our functionalized Microspheres (see our Technical Data Sheets).

We offer a large range of sizes (from 50 nm to 2 µm and more), making this range suitable for most microspheres-based technologies.

Our Microspheres are worldwide used for the following applications:
• Immunoturbidimetric and Nephelemetric Assays
• Enhanced Immunoturbidimetric Assays
• Latex Agglutination Test "LAT"
• Solid phase ImmunoAssays
• Microspheres capture ELISA

Our Microspheres are currently made by emulsion polymerization using different type of surfactants which usually are negatively charged.
Once adsorbed onto the surface of the microspheres, those surfactants induce an increased colloidal stability.

On the other hand, surfactants are well known for interfering with the binding or coupling of proteins onto the microspheres.Then, it is recommended to remove all surfactant, by additional washing steps. Most of the microspheres developers and users know how tedious washing steps are with small microspheres. For an efficient washing procedure, small microspheres need to be first centrifuged at a high speed and then they must be completely redispersed in an appropriate buffer.

Recently, our chemists have come over with new Surfactant Free products.

Most of the Microspheres developers know how tedious washing steps are with small polystyrene microspheres (low sedimentation behaviour even when centrifuged at high speed). Microspheres greater in density than 1.06 (for polystyrene) are more easily spun down.

Hydrophilic microspheres such as COOH-modified ones are less likely to clump irreversibly during the centrifugation washing process.

With a high density (1.2g/cm3) and a very high concentration up of COOH groups (>400 µEq/g), our chemists have come with new High Density COOH-Microspheres.

Very Small and Standard Carboxyl-Modified Microspheres (-COOH)

Standard Carboxyl-Modified Microspheres (-COOH)

Large Carboxyl-Modified Microspheres (-COOH)

Very Small Amino-Modified Microspheres (-NH2)

Amino-Modified Microspheres (R-NH2)

Standard Amino-Modified Microspheres (Ar-NH2)

Hydroxyl-Modified Microspheres (-OH)

Sulfite-Modified Microspheres (-SO3H)

Quatenary Ammonium-Modified Microspheres [(-CH3)3N+)]

Chloromethyl-Modified Microspheres (-CH2Cl)

Sulfate-Modified Microspheres (-SO4H)

Surfactant-Free Polystyrene Microspheres (Density: 1.059 g/cm3)

High Density COOH-Polystyrene Microspheres (Density: 1.2g/cm3)

Low Density Microspheres (Density: 1.02g/cm3)

Carboxyl-Modified Microspheres (-COOH)

Amide-Modified Microspheres (-CONH2)

Evaluation Kits

To enable you to test several types of microspheres of different size, surface or density, we offer you kits of 5 white microspheres. Our evaluation kits of white microspheres consist in 5 vials of 5ml (kit 5 x 5), 5 vials of 10ml (kit 5 x 10) or 5 vials of 50ml (kit 5 x 50).