Particles

Polystyrene microparticles
These monodisperse polystyrene microparticles, also called Latex-microspheres, are used in a wide range of immunodiagnostic assays, as size-standards for calibration of equipment, in cellbiology applications etc. The physical adsorption of the polystyrene particles is used to bind ligands to the surface of the particles.Some polystyrene particles can be offered with special modifications e.g. acrylate, epoxy, NI-NTA, collagen or Au, please ask for quotation.

Polystyrene microparticles, carboxylated
Monodisperse polystyrene microparticles, which contain carboxyl groups at the surface. They are used for passive adsorption or covalent binding of proteins.

Polystyrene microparticles, amino modified
Monodisperse polystyrene microparticles, which contain amino groups at the surface. They are used for covalent binding of proteins with the glutaraldehyde methode.

Polystyrene Microparticles, Ni-NTA modified
These beads with nickel(II)-nitrilotriacetic acid complex (Ni-NTA) are useful for binding of histidine labeled proteins in the size range of 1,0 µm to 12 µm.Recombinant proteins containing a 6xhistidine-tag can be purified by Ni-NTA chromatography which is based on the interaction between a transition Ni2+ ion immobilized on the particle matrix and the histidine side chains. Following washing of the matrix 6xhistidine-tag fusion proteins can be eluted by adding free imidazole or EDTA or by reducing the pH.

Polystyrene non-fluorescent colored microparticles
These polystyrene microparticles are prepared by polymerizing non-fluorescent dye in the styrene. The particles are free of solvent commonly found when particles are prepared by staining with a solution of dye in inorganic solvent. The intensely colored particles enhance the visual detection in assays such as latex agglutination, dipstick and membrane based assays.The polystyrene particles are offered in 5% aqueous suspension, exept PPsB-7.0, which is 1%

Coated Polystyrene Particles
The coated microparticles are prepared either by passive adsorption or covalent coupling depending upon the intended applications. The avidin and biotin coated particles are prepared by covalent coupling. Even through the 0,7 - 0,9µ Goat anti-mouse IgG coated polystyrene particles are prepared by using passive adsorption, the coated particles are stable for several years under proper storage conditions.Some typical data for Avidin polystyrene particles (0,8µ) are:Covalently coated with egg white avidin, avidin content 14 µg/mg solid, 0.212 nmole/mg solidBinding capacity to Biotin-Fluorescein 0,46 nmole/mg solidAntibody coated polystyrene particles (0,8µ):Antibody contents 14µg/mg solid, 0,2µg/cm2, 1,5 x 10⁴ IgG/particle, binding capacity to IgG-FITC 4µg/mg

Coated Fluorescent Polystyrene Particles

FITC Polystyrene Particles for Flow cytometry
The FITC labeled polystyrene particles can be used as calibration particles for flow cytometry. They can also be used to cross calibrate different flow cytometers so that data can be normalized.Please note, that the size ranges stated below are nominal, the actual size of these monodisperse particles is stated on each bottle.

Easy Calibration Fluorescent Particles
The Easy Calibartion Fluorescent particles are usewd to detect changes within the flow cytometer such as contaminats or pH changes.The beads consits of a mixture of particles with intensities calibrated in terms of "Molecules of Equivalent Fluorochrome" (MEF) units.They are offered with three different fluorochromes including FITC,PE and PE-Cy-5.Since each Easy Calibration Fluorescent Particle population is assigned a MEF unit, linearity calibrations and quantitative determinations can be performed. A linearity calibrations is performed by graphing each population´s channel number against it assigned MEF value. As a result, a regression line is created. This line can be used to track the performancy history of the instrument.

Ultra Rainbow Calibration Particles
A new type of Calibration Particles is now available for performance tracking of flow cytometers (e.g. BD FC-500, Partec, LSR Ia & II, Canto) with fluorescet channels in the Far Red. They are available in 3.8 µ or 5.05 µ. The Ultra Rainbow Calibration Particles have improved resolution in the PE-Cy7, APC and APC-Cy7 channels. These particles are supplied as a kit with 3 ml of blank particles and 2 ml of fluorescent particles.The histograms showing individual peaks of cat.# P-URCP-3.8

Ultra Rainbow Fluorecent Calibration Particles
New flow cytometers with increasing numbers of fluorescent channels in the UV and Far Red and the availablity of corresponding fluorescent conjugates are now available.In order to keep up, we have developed the Ultra Rainbow Fluorescent Particles with enhanced UV and Far Red fluorecence intensity. The beads contain a single peak and are designed for checking the optical alignment of any flow cytometer in all channels.

COMPtrol Particles
The COMPtrol particles are coated with Goat anti-Mouse Ig (H&L). They bind to fluorochrome-conjugated monoclonal mouse antibodies used during cell staining.These particles provide a method for the quality control of these conjugates. They are also used ti aid in setting proper compensation to reduce the cross-talk between the channels of multicolor flow cytometers.

Drop Delay Calibration Particles
The Drop Control Calibration particles are fluorescent particles to aid in the determination of the drop delay value for flow cytometer sorters with the appropriate attachement. As a result of using the Drop Delay Calibration particles and the appropriate attachment, the accuracy and productivity during sorting is enhanced

Rainbow Calibration Particles
Our calibration particles are designed for routine calibration of flow cytometers and are used extensivly for QC and long term performance tracking of flow cytometers. They can also be used for routine alignment and calibration in fluorescence and confocal fluorescence microscopy. All calibration particles are supplied in dropper bottles containing 5 x10 6 particles.Rainbow Calibration Particles are a mixture of fluorophores that allows exitation at any wavelength from 365 to 650nm. It enables calibration of all channels of the flow cytometer with same set of particles in similiar size, but with different intensities.Rainbow Fluorescent Particles are similiar to the above described, exept these represent single peak, uniform size particles. The Rainbow fluorescent Particles are usually the brightest peak of the corresponding Calibration Particles with the exeption of P-RFPM-3.0, which has fluorescent intensity of the stained cells. Since these particles contain single peak with very small flluorescence and size CV, they are very useful in the alignment of the optical system of the flow cytometer.Yellow Calibration Particles are designed for routine calibration of the fluorescin channel. They contain a set of similiar size Yellow Particles with different fluorescence intensities.Rainbow Linear Calibration Particles are designed to check the linearity of the PMT in the linear scale of all available channels.They are also useful for quantifying the DNA content of cells stained with Hoechst dye, DAPI, Ethidium bromide, Propidium bromide, YOYO or TOTO.Allophycocyanin Calibration Particles contain a mixture of 3.0µ fluorescent particles with different intensity in Allophycocyanin channel and can be exited with either a He-Ne laser at 632 nm or a diode laser at 635nm.Blank Calibration Particles are the blank peak of the corresponding Rainbow Calibration Particles. These particles can be used to set the threshold of the instrument in each channel.

Rainbow Fluorescent particles

Blank Calibration particles

Fluorescent Particle Kits
The Pink Fluorescent Particle Kits consist of either 3.6µ or 2,8µ Fluorescent Particles with twelve different fluorescence intensities in PE channel. They are designed to simplify the multiplex assay development using any flow cytometer. Low cost FITC conjugates can be used for detection. They are supplied as kits of either six odd numbered peaks or six even numbered peaks. Four different Pink Fluorescent Particle Kits are available for different applications.The Yellow Fluorescent Particle Kits consist of 2,8µ and 3,6µ Yellow Fluorescent Particles in multiple fluorescence intensities in FITC channels. These two kits can be used to develop multiplex assays using either PE or PE-Cy5 tracers for detection.

Fluorescent Polystyrene Particles

Large Size Particles
In the following chapter we offer some beads of larger sizes but with relative narrow size distribution. The offered quantities are laboratory quantities and all beads can be offered as bulk quantities also. The beads are used for different applications, e. g. manufacturing of implatates( pmma-beads and pharmaceutical synthetic research (polystyrene beads).