柱状黄杆菌双抗体夹心ELISA检测方法的建立

Establishment of a Double Antibody Sandwich ELISA for the Detection of Flavobacterium columnaris

为快速检测柱状黄杆菌,本研究以纯化的柱状黄杆菌单克隆抗体为捕获抗体,以多克隆抗体为检测抗体,建立了双抗体夹心ELISA(DAS-ELISA)检测法。最佳的方案为用0.08μg/孔纯化的单克隆抗体4℃包被过夜,30g/L牛血清白蛋白37℃封闭90min,多克隆抗体的工作浓度为0.11μg/孔,检测抗原、多克隆抗体、酶标抗体均为37℃作用1h,显色15min后终止反应,当D492nm值≥0.776且P/N≥2.1时判定为阳性。该方法特异性强,与迟钝爱德华氏菌、大肠杆菌、嗜水气单胞菌、鳗弧菌、溶藻弧菌、副溶血弧菌、哈维氏弧菌等水产病原菌均无交叉反应。最低检测剂量为1×103 CFU。本研究首次建立了检测柱状黄杆菌的双抗体夹心ELISA方法,经验证该方法特异性强、灵敏度高。

The aim of this study was to develop a rapid method for the detection of Flavobacterium columnaris based on a double antibody sandwich ELISA （DAS-ELISA）. Purified monoclonal antibody against Flavobacterium columnaris was used as the capture antibody, while polyclonal antibody was used as the detection antibody. The optimal conditions for the ELISA were as follows： monoclonal antibody with 0.08μg per well was added to coat overnight at 4 ℃ ; the plate was blocked by 30 g/L bovin serum albumin for 90 min at 37 ℃ ; incubation concentration of polyclonal antibody was 0.11 μg per well; the incubation time for detection antigen, polyclonal antibody and enzyme labeled antibody was 1 h at 37 ℃ for each; the value of D492 nm was obtained after 15 min coloration. Judging with P/N≥2.1 and D492 nm≥0. 776 as positive criteria. This method had no cross re- action with Edwardsiella tarda , E. coli, Aeromonas hydrophila , Vibrio anguillarum , Vibrio alginolyticus , Vibrio parahae- molyticus and Vibrio harveyi. Its minimum detectable limit was 1 × 10^3 CFU. Therefore, this study provided a specific and sensitive detection method for Flavobacterium columnaris for the first time.