Suspension array

Stevens P.W., Wang C.H.J., Kelso D.M., Immobilized particle arrays coalescence of planar- and suspension-array technologies, Anal Chem 2003 75 1141-1146. 

Armstrong, B. et al. (2000) Suspension arrays for high throughput, multiplexed single nucleotide polymorphism genotyping. Cytometry 40, 102-108. 

Abstract Dye-doped polymeric micro- and nanobeads represent smart analytical tools that have become very popular recently. They enable noninvasive contactless sensing and imaging of various analytical parameters on a nanoscale and are also widely employed in composite sensing materials, in suspension arrays, and as labels. This contribution gives an overview of materials and techniques used for preparation of dye-doped polymeric beads. It also provides examples of bead materials and their applications for optical sensing and imaging. 

Fluorescent encoded beads represent the largest group in multiplexed suspension arrays (Fig. 6c). Luminescent dyes are commonly incorporated by swelling. The... 

Fig. 6 (a) Schematic illustration of a flow cytometer used in a suspension array. The sample microspheres are hydrodynamically focused in a fluidic system and read-out by two laser beams. Laser 1 excites the encoding dyes and the fluorescence is detected at two wavelengths. Laser 2 is used to quantify the analyte, (b) Scheme of randomly ordered bead array concept. Beads are pooled and adsorbed into the etched wells of an optical fiber, (c) Scheme of randomly-ordered sedimentation array. A set of encoded microspheres is added to the analyte solution. Subsequent to binding of the analyte, microparticles sediment and assemble at the transparent bottom of a sample tube generating a randomly ordered array. This array is evaluated by microscope optics and a CCD-camera. Reproduced with permission from Refs. [85] and [101]. Copyright 1999, 2008 American Chemical Society... 

A new suspension array concept based on sedimentation and microscopic imaging was introduced by Moser et al. [98], Magnetic microbeads settle to the bottom of a microplate well by magnetic forces and form randomly ordered arrays, which are examined by fluorescence microscopy and automated imaging analysis. Each bead carries specific capture molecules and can be identified by a defined luminescent code. 

Nolan JP, Sklar LA (2002) Suspension array technology evolution of the flat-array paradigm. Trends Biotechnol 20 9-12... 

Suspension arrays are based on addressable nano- or micrometric beads of various chemical natures (polymeric, silica, gold) and architectures (uniform composition, core-shell particles) to which NAs can be immobilized by means of activating chemistries similar to those described for fiat supports [64,65] depending on the composition of the particles outmost layer. 

Homogeneous Phase Bead Biochips Suspension Array Technology. 121... 

Wang L., Cole K. D., Gaigalas A. K., and Zhang Y. Z., Fluorescent nanometer microspheres as a reporter for sensitive detection of simulants of biological threats using multiplexed suspension arrays, Bioconjug. Chem., 16(1), 194-199, 2005. 

Khan, I. H., S. Mendoza, P. Rhyne, M. Ziman, J. Tuscano, D. Eisinger, H. J. Kung, and P. A. Luciw. 2006. Multiplex analysis of intracellular signaling pathways in lymphoid cells by microbead suspension arrays. Mol. Cell Proteomics... 

Overviews of recent developments in beads, including fluorescent ones, have been provided by The Latex Course, recently sponsored by Bangs Laboratories. Also, the most recent edition of the nuts-and-bolts book of flow cytometry provides an update on literature in the area of bead probes. Furthermore, the International Federation of Clinical Chemistry (IFCC) Working Group on Nanotechnology, chaired by Larry J. Kricka (University of Pennsylvania Medical Center), has recently compiled literature on microarrays and microchips, the fourth part of which will cover literature on protein, peptide, and antibody microarrays and microchips to the middle of 2003, and will be made available via the IFCC web page. The latter literature includes that of bead suspension arrays. 

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