Polystyrene-maleic (PSM) Beads Polystyrene-maleic (PSM) Beads 
Multiplexed analysis systems (MAS) are of importance not only in bioanalytics and chemoanalytics, including genomics, proteomics, immunology, drug screening, and combinatorial chemistry but also for environmental pollution monitoring. One can distinguish between two classes of MAS: flat-surface microarrays (biochips) and suspension microarrays. In contrast to conventional microslides and other carrier-bound arrays, suspension arrays consist of a multitude of microparticles (microspheres, microbeads) floating in solution. Suspension arrays offer advantages in handling, higher flexibility in array creation and faster reaction kinetics. Several measurement platforms based on optically addressable encoded microbeads have been developed or are currently in development. Optical addressable encoding is based on use of luminescent dyes - so-called classification dyes. According to this method, each class of microspheres has incorporated at least two different classification dyes and thus is encoded with a "dye signature", which can be either based on the intensity and/or luminescence decay time.
Polystyrene-maleic (PSM) beads have large number of carboxylic groups on their surface. These groups ensure high hydrophilicity of the beads and allow to make a chemical modification of the bead surface. Therefore, the PSM beads are very convenient to design various suspension microarrays for MAS.