Particle shape analysis is an important tool for estimating particle behavior or particle properties. This opens up new possibilities for application-oriented design and the selection of adequate particles. Available monodisperse reference particles are mostly spherical. The Dr. Lerche KG developed novel shape-defined microparticles, which are characterized by a uniform geometric, non-spherical shape.

With the help of these shape reference particles, the performance of devices for particle shape analysis can be tested and, in addition, their algorithms can be validated and optimized. They are also used in the quality control of the manufacturer in the production of shape analysis equipment and in the performance verification of the meter at the user.

The form-defined reference particles have a rotationally symmetric prolate ellipsoidal shape with an equivalent circular diameter of 25 µm to 35 µm and an aspect ratio of 0.5 to 0.7. They are characterized by a high degree of isomorphism in terms of their shape and size (standard deviation below 15%).

Typical images of suspended, stretched elliptical reference particles

The particles are available as a suspension (ethanol / water (50/50)) and as dry particles. For individual applications, the suspended particles can be diluted with aqueous solutions, ethanol or acetone to the desired particle concentration. Dry particles are only to be used as dry powder. The shelf life is six months.

The reference particles show autofluorescence in green light (λ_ex: 450-490 nm Bandpass filter, λ_em: 515 nm Longpass filter) und im roten Wellenlängenbereich (λ_ex: 510-560 nm Bandpassfilter, λ_em: 590 nm Langpassfilter). Due to this property, they can also be used in analyzers with fluorescence detection without additional dye binding.

Microscopic images of ShapeControl microparticles using CLSM in fluorescence mode (left) and in white light mode (right) (fluorescence λex:488 nm)

The particle size and shape reference values are supplied with a test certificate attached to each sample. The shape of the particles is described by geometric macroform descriptors according to the   ISO   9276-6: 2008.