Lateral Flow Immunoassay For Rapid Detection Research Articles

An up-conversion fluorescence lateral-flow immunoassay for rapid detection of Daratumumab in serum protein electrophoresis clinical samples

BackgroundDaratumumab (DARA) is a commonly used monoclonal antibody (mAb) drug for the treatment of multiple myeloma (MM). Its appearance as a visible abnormal band in the γ-region of a serum protein electrophoresis (SPEP) gel may interfere with the SPEP result interpretation. With the advantages of portability and rapid testing capabilities, up-conversion fluorescence lateral-flow immunoassay (LFA) can be an ideal solution to detect DARA interference. MethodsAn up-conversion fluorescence LFA strip was designed and constructed to perform semi-quantitative DARA testing in clinical samples. The LFA strip test was evaluated for limit of detection (LOD), dynamic range, and analytical interference. ResultsTo demonstrate the clinical utility of the LFA strip, 43 SPEP-positive patient serum samples were tested for the presence of DARA, and the results exactly matched the DARA usage history in patient medical records. ConclusionsThe performance of the up-conversion fluorescence LFA strip meets the purpose of clarifying DARA interference in SPEP results. It may be used as an independent and objective confirmation of the presence of DARA in clinical samples. The LFA strip offers a cost-effective rapid on-site test to check for DARA interference alongside standard SPEP equipment, which significantly improves the interpretation of ambiguous SPEP results involving DARA, and does not intervene the current SPEP workflow in clinical laboratory practice.

Development of nanobody-based flow-through dot ELISA and lateral-flow immunoassay for rapid detection of 3-phenoxybenzoic acid.

As a major metabolite of pyrethroid pesticides, 3-phenoxybenzoic acid (3-PBA) can be an indicator of health risk and human exposure assessment. Based on nanobodies (Nbs), we have developed a rapid flow-through dot enzyme linked immunosorbent assay (dot ELISA) and gold nanoparticle (GNP) lateral-flow immunoassay for detecting 3-PBA. The limit of detection (LOD) values for detecting 3-PBA by flow-through dot ELISA and GNP lateral-flow immunoassay were 0.01 ng mL-1 and 0.1 ng mL-1, respectively. The samples (urine and lake water) with and without 3-PBA were detected by both nanobody-based flow-through dot ELISA and GNP lateral-flow immunoassay, as well as liquid chromatography-mass spectrometry (LC-MS) for validation. There was good consistency between the results of the immunoassays. This demonstrated that the two developed nanobody-based immunoassays are suitable for rapid detection of 3-PBA.

Quantum dot-based lateral-flow immunoassay for rapid detection of rhein using specific egg yolk antibodies

The lateral-flow immunoassays based on novel fluorescent labels have been receiving increasing attention. Here, we developed a rapid, quantitative, lateral-flow immunoassay for rapid and accurate detection of rhein (RHE). The competitive immunoassay used anti-RHE IgY (immunoglobulin of yolk) probe conjugated with QDs as reporter. Our results showed that the immunochromatographic strip can be applied for qualitative and quantitative analysis of RHE in samples. For quantitative analysis, the strips were scanned by a membrane-strip reader, and a detection curve (y = −0.128ln(x) + 1.7627, correlation coefficient = 0.9792) representing the averages of the scanned data was obtained. The detection range was 80–5000 ng mL−1 and the qualitative-detection limit for RHE was 98.2 ng mL−1. To our knowledge, this is the first report of the quantitative detection of a natural product by QDs-IgY immunochromatography, which creates a new strategy to detect the harmful or index component of TCM and may be applied as a supplement or alternative to instrument detection.