Ligand binding assay support specificity

The focus of this chapter is on automating ligand-binding assays in support of clinical and nonclinical studies. This chapter will not specifically address laboratory software systems or LIMS, although many of the tools for implementing laboratory automation can be applied to these systems as well. 

A second form, the sandwich immunoassay, is based on noncompetitive binding and involves two separate Ag/Ab interactions (Wisdom, 1976). Typically Ab is attached to a solid support and exposed to a sample containing the Ag of interest as depicted in Fig. 1. The amount of Ag bound to the solid phase-Ab is determined following incubation with a second ligand-specific labeled Ab (Ab ). In contrast to a competitive assay, the amount of Ab-bound Ag, and therefore the amount of enzyme label, is proportional to the Ag concentration in solution. 

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