Development of an Immunoassay-Based Lateral Flow Dipstick for the Rapid Detection of Aflatoxin B₁ in Pig Feed

Abstract

The aim of this work was to develop an immunoassay-based lateral flow dipstick for the rapid detection of aflatoxin B(1) in pig feed. The test consisted of three main components: conjugate pad, membrane, and absorbent pad. The membrane was coated with two capture reagents, that is, aflatoxin B(1)-bovine serum albumin conjugate and rabbit anti-mouse antibodies. The detector reagent consisted of colloidal gold particles coated with affinity-purified monoclonal anti-aflatoxin B(1) antibodies, which saturated the conjugate pad. A comparison of several extraction methods for the pig feed matrix is presented. A mixture of methanol/water (80:20, v/v) gave the best recoveries. After sample extraction and dilution, the dipstick was put in the sample solution at the conjugate pad side and developed for 10 min. Analyte present in the sample competed with the aflatoxin B(1) immobilized on the membrane for binding to the limited amount of antibodies in the detector reagent. Thus, the line color intensity of an aflatoxin B(1)-positive dipstick is visually distinguishable from that of an aflatoxin B(1)-negative sample. The visual detection limit for aflatoxin B(1) is 5 microg/kg. The major advantages of this one-step striptest are that results can be obtained within 10 min and that all reagents are immobilized on the lateral flow dipstick.

Lateral Flow Immunoassay Using Europium Chelate-Loaded Silica Nanoparticles as Labels

“…However, LFIA has primarily been used for qualitative testing in which the analytes are present at relatively high concentrations. The major reasons for this limited use of LFIAs are the low signal intensity (1 ) and poor quantitative discrimination (2, 3 ) of the color-formation reaction based on label accumulation (4,5 ). Although researchers have tried to use instrumental means to generate quantitative results (6,7 ), the relatively low signals obtained often make such efforts meaningless (1 ).…”

Stable recombinant alpaca antibodies for detection of Tulip virus X

“…Examples are the development of easy-to-handle, field-compatible tests such as lateralflow (Delmulle et al 2005), but also more complex test set-ups like flow-cytometry (Chitarra et al 2002), and multiplex detection using Luminex (Rao et al 2004;Peters et al 2007) or protein chips (Taitt et al 2004). Use of recombinant antibodies, fused to specific tags, may facilitate multiplex design (Wingren and Borrebaeck 2006).…”

Effect of the oriental and yellow mustard flours as natural preservative against aflatoxins B1, B2, G1 and G2 production in wheat tortillas

“…Although more than 20 AFs have been identified, the major AFs of concern are known as B 1 (AFB 1 ), B 2 , G 1 and G 2 . Among them, AFB 1 is normally the most prevalent toxin and the most toxic (Delmulle et al 2005;Zhang et al 2009). As a result, many countries have regulatory limits for AFB 1 levels in agricultural products.…”