Immunoassay as an Analytical Tool in Agricultural Biotechnology

Abstract

Immunoassays for biotechnology engineered proteins are used by AgBiotech companies at numerous points in product development and by feed and food suppliers for compliance and contractual purposes. Although AgBiotech companies use the technology during product development and seed production, other stakeholders from the food and feed supply chains, such as commodity, food, and feed companies, as well as third-party diagnostic testing companies, also rely on immunoassays for a number of purposes. The primary use of immunoassays is to verify the presence or absence of genetically modified (GM) material in a product or to quantify the amount of GM material present in a product. This article describes the fundamental elements of GM analysis using immunoassays and especially its application to the testing of grains. The 2 most commonly used formats are lateral flow devices (LFD) and plate-based enzyme-linked immunosorbent assays (ELISA). The main applications of both formats are discussed in general, and the benefits and drawbacks are discussed in detail. The document highlights the many areas to which attention must be paid in order to produce reliable test results. These include sample preparation, method validation, choice of appropriate reference materials, and biological and instrumental sources of error. The article also discusses issues related to the analysis of different matrixes and the effects they may have on the accuracy of the immunoassays.

Development of a Rapid Point-of-Use DNA Test for the Screening of Genuity® Roundup Ready 2 Yield® Soybean in Seed Samples

“…NAATs owe their increasing popularity to their extremely high sensitivity, specificity, speed, and operational simplicity. NAATs, in fact, increasingly complement or may replace traditional methods such as culturing techniques [4][5][6] and antibody-based protein detection techniques [7][8][9].…”

“…Protein-based lateral-flow devices (LFD) are the current gold standard for the rapid, on-site test format for GMO sample screening [8,9,32]. LFD-based screening is used at different points in the grain trade, including farms, grain elevators, and ports to test for different GMO traits to support consumer preferences and trade requirements.…”

Explanatory note on the determination of newly expressed protein levels in the context of genetically modified plant applications for EU market authorisation

“…The NEP analytical methods discussed in this document are antibody-based methods such as ELISA and immunoblotting/western blot analysis as well as mass spectrometry (MS) methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) (e.g. Andreasson et al, 2015;Crespo et al, 2008;Grothaus et al, 2006;Kruve et al, 2015a,b;Liebler and Zimmerman, 2013;Pan et al, 2009;Schmidt and Alarcon, 2011;Settlage et al, 2017). These methods are the most commonly used approaches for NEP quantification reported in dossiers submitted for GM market authorisation in the EU.…”

Rapid detection of proteins in transgenic crops without protein reference standards by targeted proteomic mass spectrometry

“…Immunoassays, such as western blots and ELISAs (enzyme linked immunosorbent assays), have long been the primary method for target protein detection and quantification in biological samples, including transgenic crops. 1 ELISAs have remained a popular choice because of the throughput, sensitivity and selectivity. The drawback to ELISAs and other immunoassays is the need for high-quality antibodies that may not be readily available and the significant time (approximately 10-20 months) and resources needed to develop an assay.…”