Chemical assays--new opportunities.

The acceptance of the solid-phase format in various areas of clinical chemistry is the consequence of the advantages of this test format, which include stability of the reagents, unitized packaging, convenient and small instruments, and minimal preparations by users before testing. Overall, these advantages provide very convenient tests. Future successful uses of solid-phase reagents depend upon how well these features meet the needs of the users. Needs for systems to be used in the decentralized laboratory include even less cost, even more convenience, and improved quality control. Needs for home testing include convenient tests with clinically useful accuracy, improved quality control, and improved recording systems to overcome user bias in recording results. New solid-phase technologies being developed include noncolorimetric systems suitable for use with miniature probes, for in vitro or in vivo use, and spectrophotometric systems for determinations of analytes directly in capillaries of the skin without invasive sampling.