scholarly journals Development of a Nanobody–Alkaline Phosphatase Fusion Protein and Its Application in a Highly Sensitive Direct Competitive Fluorescence Enzyme Immunoassay for Detection of Ochratoxin A in Cereal

2015 ◽  
Vol 87 (2) ◽  
pp. 1387-1394 ◽  
Author(s):  
Xing Liu ◽  
Yang Xu ◽  
De-bin Wan ◽  
Yong-hua Xiong ◽  
Zhen-yun He ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Fusion Protein ◽  
Enzyme Immunoassay ◽  
Ochratoxin A ◽  
Highly Sensitive

scholarly journals Nanobody-Alkaline Phosphatase Fusion Protein-Based Enzyme-Linked Immunosorbent Assay for One-Step Detection of Ochratoxin A in Rice

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4044 ◽  
Author(s):  
Zhichang Sun ◽  
Xuerou Wang ◽  
Qi Chen ◽  
Yonghuan Yun ◽  
Zongwen Tang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Fusion Protein ◽  
Ochratoxin A ◽  
Immunosorbent Assay ◽  
Limit Of Detection ◽  
Binding Capacity ◽  
Cross Reactivity ◽  
Solvent Tolerance ◽  
Enzyme Linked Immunosorbent Assay ◽  
One Step

Ochratoxin A (OTA) has become one a focus of public concern because of its multiple toxic effects and widespread contamination. To monitor OTA in rice, a sensitive, selective, and one-step enzyme-linked immunosorbent assay (ELISA) using a nanobody-alkaline phosphatase fusion protein (Nb28-AP) was developed. The Nb28-AP was produced by auto-induction expression and retained an intact antigen-binding capacity and enzymatic activity. It exhibited high thermal stability and organic solvent tolerance. Under the optimal conditions, the developed assay for OTA could be finished in 20 min with a half maximal inhibitory concentration of 0.57 ng mL−1 and a limit of detection of 0.059 ng mL−1, which was 1.1 times and 2.7 times lower than that of the unfused Nb28-based ELISA. The Nb28-AP exhibited a low cross-reactivity (CR) with ochratoxin B (0.92%) and ochratoxin C (6.2%), and an ignorable CR (<0.10%) with other mycotoxins. The developed Nb-AP-based one-step ELISA was validated and compared with a liquid chromatography-tandem mass spectrometry method. The results show the reliability of Nb-AP-based one-step ELISA for the detection of OTA in rice.

One-step detection of ochratoxin A in cereal by dot immunoassay using a nanobody-alkaline phosphatase fusion protein

Food Control ◽  
2018 ◽  
Vol 92 ◽  
pp. 430-436 ◽  
Author(s):  
Zongwen Tang ◽  
Xuerou Wang ◽  
Jingwen Lv ◽  
Xiangrong Hu ◽  
Xing Liu
Keyword(s):  
Alkaline Phosphatase ◽  
Fusion Protein ◽  
Ochratoxin A ◽  
Step Detection ◽  
One Step ◽  
Dot Immunoassay

scholarly journals Development of an Anti-Idiotypic VHH Antibody and Toxin-Free Enzyme Immunoassay for Ochratoxin A in Cereals

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 280 ◽  
Author(s):  
Caixia Zhang ◽  
Qi Zhang ◽  
Xiaoqian Tang ◽  
Wen Zhang ◽  
Peiwu Li
Keyword(s):  
Enzyme Immunoassay ◽  
Ochratoxin A ◽  
High Performance ◽  
Elisa Test ◽  
Hplc Method ◽  
Free Enzyme ◽  
Agricultural Products ◽  
Enzyme Linked Immunosorbent Assay ◽  
Highly Sensitive ◽  
Ic50 Value

Enzyme-linked immunosorbent assay (ELISA) test kits have been widely used for the determination of mycotoxins in agricultural products and foods, however, this test uses toxin standards with high toxicity and carcinogenicity that seriously threaten human health. In this work, the anti-idiotypic nanobody VHH 2-24 was first developed and then, using it as a surrogate standard, a toxin-free enzyme immunoassay for ochratoxin A (OTA) was established. The IC50 value of the VHH 2-24 surrogate standard-based ELISA was 0.097 µg/mL, with a linear range of 0.027–0.653 µg/mL. The average recoveries were tested by spike-and-recovery experiments, and ranged from 81.8% to 105.0%. The accuracy of the developed ELISA for detecting OTA was further verified by using the high performance liquid chromatography (HPLC) method, and an excellent correlation was observed. In summary, the toxin-free ELISA established in this study proves the latent use of the anti-idiotypic VHH as a surrogate calibrator for other mycotoxins and highly toxic small molecule analysis to improve assay properties for highly sensitive analyte determination in agricultural products.

A highly sensitive sandwich enzyme immunoassay of urinary growth hormone in children with short stature, Turner's syndrome, and simple obesity

1989 ◽  
Vol 121 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Hiroshi Tomita ◽  
Masamichi Ogawa ◽  
Takashi Kamijo ◽  
Osamu Mori ◽  
Eiji Ishikawa ◽  
...  
Keyword(s):  
Short Stature ◽  
Enzyme Immunoassay ◽  
Gh Deficiency ◽  
Urine Samples ◽  
Turner's Syndrome ◽  
Turner’S Syndrome ◽  
Highly Sensitive ◽  
Significant Difference ◽  
Simple Obesity ◽  
Sandwich Enzyme Immunoassay

Abstract. GH values were determined by a highly sensitive sandwich enzyme immunoassay in the 1st morning and/or 24-h accumulated urine samples in 94 children (short stature 70, including 14 with complete GH deficiency, 9 with partial GH deficiency, and 47 with GH-normal short stature; Turner's syndrome, 10, and simple obesity, 14). GH values were also determined in the 2nd to 4th urine samples taken on the same day together with the 1st morning urine in 5 of them. GH values in the 1st morning urine correlated significantly with those of the 24-h urine and with serum peak and mean GH values during nocturnal sleep as a physiological GH secretion test. The 2nd to 4th urines had lower GH concentrations than the 1st morning urine. The GH value of the 1st morning urine in complete GH deficiency was significantly lower than those in GH-normal short stature, partial GH deficiency and Turner's syndrome. However, no significant difference was detected in urinary GH values between complete GH deficiency and simple obesity. We conclude that 1st morning urinary GH estimation may be useful for differentiation of complete GH deficiency from other causes of short stature, but may be difficult for the distinction between complete GH deficiency and obesity with normal GH secretory ability.

Sign in / Sign up

Export Citation Format

Share Document