Development of A Monoclonal Antibody‐Based Competitive Elisa Method for Quantitative Detection of Dextran

Abstract

To solve processing problems caused by bacterial activity in sugar industry, a sensitive method for dextran detection is expected. In this study, monoclonal antibodies (mAbs) against dextran were prepared using dextran T40 conjugated with bovine serum albumin as immunogens. Basing on the mAbs, a competitive enzyme-linked immunosorbent assay (ELISA) method to measure dextran quantitatively was developed. Results demonstrated that this competitive ELISA method had a calibration curve with correlation coefficient of 0.9986, IC 50 value of 204.2 ng/mL and detection value ranging from 26.3 ng/mL to 1174.9 ng/mL. In addition, cross-reaction assay suggested the method had no significant crossreaction with dextran-related substances such as b-glucan, starch, sucrose, sugar and glucose. Besides, spike recovery assay indicated this quantitative method for dextran detection had a perfect accuracy. PRACTICAL APPLICATIONSWith wide detection range, high specificity and good calibration curve, this developed competitive ELISA method will be reliable to detect dextran quantitatively in sugar industry, and even may be commercially applied into kit development.

Development of a multicolor upconversion fluorescence immunoassay for the simultaneous detection of thiamethoxam and dextran by magnetic separation

“…The sensitivity of the presented mAb was better than that of the mAb prepared by Wang et al (IC 50 of 204.2 ng mL −1 in ic-ELISA). 21 …”

“…For dextran, the alcohol haze method 10 and Roberts' copper method 11 have been widely used in the sugar industry, but their sensitivity and specificity are unsatisfactory. 12 The enzyme-HPLC method 13 and Optical Activity Ltd. Polarimetric Method (DASA) 14 have great sensitivity and specificity, but the test cost is high, and the test cannot be used routinely in the sugar industry.…”

“… 19 For dextran, Liang et al reported an anti-dextran mAb and immunonephelometry for the quantitative detection of dextran. 20 Wang et al developed a mAb-based sandwich ELISA (limit of detection, LOD of 3.9 ng mL −1 ) 21 and competitive ELISA (IC 50 of 204.2 ng mL −1 ) 22 for dextran. However, there is currently no method for the simultaneous detection of thiamethoxam and dextran.…”