double-labeled microsphere from the FocalCheck DoubleGreen Fluorescent Microsphere Kit

Optimize our particles for your particular application and need

We can prepare unstained, colored, magnetic and fluorescently stained polystyrene microspheres for a variety of industrial and research applications. Our custom microsphere service is efficient and confidential, and we guarantee the quality of our work.

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Quality custom microspheres for every research need

The uses for particles are endless, but applications may include instrument calibration and size standards (e.g., for flow cytometers and microscopes), capture and detection of small molecules (e.g., lateral flow devices, diagnostic assay research, imaging, multiplexing), tracers, and sensors.

  • Well-characterized performance and high quality
  • High fluorescence, low photobleaching
  • Expert staff technical knowledge
  • Surfactant-free preparations, i.e., won’t interfere with downstream applications                                                                                         

Frequently asked questions

Standard sizes range from 0.02 to 16 µm in diameter, but we can supply larger particles depending on the specifications.

We can prepare a broad range of surfaces of polystyrene, including but not limited to: sulfate, carboxylate modified (CML), carboxyl, aldehyde/sulfate, aliphatic amine latex, amidine, and chloromethyl.

White (undyed), colored (black, yellow, green, red, blue, navy blue), fluorescent (UV- or visible- and near infrared–excitable), multi-dyed beads, and TransFluoSpheres® beads (large Stokes shift beads). We use our proprietary fluorescent dyes and incorporate our stains internally, making our fluorescent microspheres the brightest available.

We can passively adsorb molecules to the bead surface or prepare covalent adducts of proteins, fluorescent dyes, indicators, or other molecules. Because our particles are ultraclean and surfactant-free, adsorption, conjugation, and stability experiments are straightforward.

We can supply any amount from 1 mL to 50 L volumes.


FocalCheck Microspheres for confocal laser-scanning microscope alignment

Our patented FocalCheck fluorescent microspheres are specifically designed for examining the alignment, sensitivity, and stability of confocal laser-scanning microscopes. They are particularly useful for confirming the optical sectioning thickness (Z-resolution) in three-dimensional imaging applications.

A. In the confocal laser-scanning microscope, separate light paths exist for UV and visible wavelengths. Also, fluorescence emitted is detected by different photomultiplier detectors. Proper optical alignment may be obtained with either of two types of FocalCheck microspheres. For example, the microspheres with orange ring stain and blue throughout allow UV visible wavelength alignment in three dimensions upon aligning the orange ring with the blue disc. Focal alignment is also possible simultaneously in three colors by aligning the green orange and dark red rings of the FocalCheck microspheres containing fluorescent green orange dark red ring stains.

B. Optical sections of eleven FocalCheck microspheres prior to aligning the microscope left and after alignment right. The position of the red-fluorescent rings reveals the degree of alignment.


Tired of adjusting your experiment to make do with off-the-shelf beads? Request a quote today* and let us make a bead designed to the specifications that work for you.
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We may already have what you need. Follow the links below to see our range of catalog microspheres products.