Material classification

SPES patented technology not only measures particles size distribution but also classifies the composition of single subvisible particle in a fluid. In fact, particles with different size, refractive index, shape, etc. draw data clouds in different positions in the 2D histogram. Specific data analysis and data reduction methods provided by EOS results in a complete selection and characterization of the particles of each composition.

(in figure) The 2D histogram reports experimental results for Poly(methyl methacrylate) (PMMA), Polystyrene (PS) and silver (Ag) spheres as compare to expected values (open circles) in the complex plane. Lines are just guides to the eye joining the open circles. As the selected materials (PMMA, PS and Ag) present different refractive indexes we can easily distinguish the different particles, recover the corresponding refractive index distribution and counts how many particles for each type are present.


SPES discriminates, measures and counts how many particles of given optical properties are present in a complex fluids as biological matrix. (in figure) SPES counts the particle numerical concentration of 500nm and 1 micron PS particles in the supernatant of three cell coltures and the numerical concentration and particle stability directly in diluted cell lysates without any purification or filtration.

PS in complex biofluid

Material classification opens up new opportunities in particles characterization: work directly in complex fluids, avoid preliminary purification process, do not care about impurities or gas bubble, and more.

The characterization of the particle composition is of capital importance for the proper characterization of particle in complex fluids, characterization of drug delivery systems, fast and effective characterization regardless the presence of impurities – e.g. no preliminary purification or filtration are required – and more.