Microspheres usually consist of a spherical shell that is usually made of a biodegradable or resorbable plastic polymer, that has a very small diameter usually in the micrometer or nanometer range, and that is often filled with a substance (as a drug or antibody) for release as the shell is degraded.
New miniaturised, high throughput technologies for bioseparation, diagnostics, DNA sequencing, flow cytometry, drug discovery, proteomics and genomics are in many instances reliant on attachment of functional biological molecules to a microsphere support.