Immunoassay of infectious agents

Abstract

Immunoassays have evolved for a broad range of applications since the pioneering work of Yalow and Berson who developed the first competitive radioimmunoassay (RIA) for human insulin in 1959. Immunoassay detection of specific antigens and host-produced antibodies directed against such antigens constitutes one of the most widely used and successful methods for diagnosing infectious diseases (IDs). The number and variety of new assay systems that are continually being developed reflect the increasing demand for immunoassays possessing greater sensitivity, speed, and ease of use. This trend has been driven, in part, by the need for improved immunodiagnostic systems to perform rapid testing and counter emerging IDs and biothreat (BT) agents. Another factor driving this trend is the need to integrate immunoassays with more sensitive nucleic acid-based methods for a comprehensive approach. Here we examine the development of immunoassays, some of the key formats used for the detection and identification of BT/ID agents, and the application of these technologies under different scenarios.

Methodologies for Identifying Microorganisms and Viruses by Mass Cataloging of RNAs

“…Despite this degenerpartial sequence verifi cation by hybridization methods (including polymerase chain reaction [PCR] and DNA arrays). Immunochemical methods such as enzymelinked immunosorbent assay ( ELISA ) and others can be used for bacterial identifi cation, however it is not clear that enough organism -specifi c antigens exist [22] . Furthermore, no generalized informational database can be leveraged to develop new immunological assays.…”

Development of Phage-Based Antibody Fragment Reagents for Affinity Enrichment of Bacterial Immunoglobulin G Binding Proteins

“…Several different platforms combining the sensitivity of antibody enrichment with the specificity of mass spectrometry analysis have been established for quantitative measurements of proteins in plasma and serum [8][9][10][11] . In addition, the use of antibodies has also become increasingly important for tracking specific microorganisms in various infectious diseases 12,13 .…”

Analysis of active ricin and castor bean proteins in a ricin preparation, castor bean extract, and surface swabs from a public health investigation

“…After incubation and plate washing to remove any unbound europium-labeled antibody, the lanthanide label is dissociated from the detector antibodies using an enhancement solution. The free europium is rapidly chelated forming a stable highly fluorescent complex that can be detected using a microplate reader [12,13].…”