摘要:
建立了一种可快速检测配方羊奶粉中牛β-乳球蛋白(β-lactoglobulin,β-lg)的胶体金免疫层析检测方法。通过杂交瘤技术制备β-lg单克隆抗体(monoclonal antibody,mAb),半抑制浓度(50% inhibiting concentration,IC50)为5.87 μg/mL。将胶体金标记的β-lg mAb包被于金标垫,β-lg和山羊抗小鼠IgG标记于硝酸纤维素膜(nitrocellulose membrane,NC膜)分别作为检测线(T线)和质控线(C线),开发了可检测β-lg的免疫层析试纸条。该试纸条对β-lg的检测限(limit of detection,LOD)值为50 μg/mL,与其他基质成分均未产生有效交叉反应,对全脂山羊乳粉中掺杂脱脂牛奶粉(nonfat skim milk,NFSM)、脱盐乳清粉(desalted whey powder,DWP)和乳清蛋白粉(whey protein powder,WPP)的LOD值分别为5%、5%和0.1%。运用该方法对9个市售配方羊奶粉进行分析,检测结果与商品化酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)试剂盒一致。该方法前处理快速简单,5 min即可裸眼判定结果,可用于配方羊奶粉商品的现场快速检测。
Abstract:
The aim of this study was to develop a colloidal gold-based immunochromatographic assay for rapid detection bovine β-lactoglobulin(β-lg)in commercial goat milk formulas. Firstly,an anti-β-lg monoclonal antibody(mAb)was prepared using the hybridoma technique with 50% inhibitory concentration(IC50)value of 5.87 μg/mL. To develop an immunochromatographic test strip for detection β-lg,gold labed β-lg mAbs were sprayed on gold conjugation pad,and nitrocellulose membrane was lined with β-lg and goat anti-mouse immunoglobulins as test line(T-line)and control line(C-line). The limit of detection(LOD)value of the test strip was 50 μg/mL for β-lg,and no effective cross-reactivities with other matrix ingredients were observed. The LOD of adulteration of whole goat milk powder with cow’s nonfat skim milk(NFSM),desalted whey powder(DWP)and whey protein powder(WPP)were 5%,5% and 0.1%,respectively. Furthermore,9 commercial goat milk formulas were analyzed by this assay,and the results were in accordance with that obtained by commercial enzyme linked immunosorbent assay(ELISA)kit. The assay includes a rapid and simple treatment of sample,could be finished in 5 min,which could be evaluated by naked-eye,was qualified for on-site monitoring goat formula milk adulteration.
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