Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork

2012 ◽  
Vol 736 ◽  
pp. 85-91 ◽  
Author(s):  
Jie-Xian Dong ◽  
Zhen-Feng Li ◽  
Hong-Tao Lei ◽  
Yuan-Ming Sun ◽  
Frédéric Ducancel ◽  
...  
2006 ◽  
Vol 78 (4) ◽  
pp. 997-1004 ◽  
Author(s):  
Shi-Hua Wang ◽  
Ji-Bin Zhang ◽  
Zhi-Ping Zhang ◽  
Ya-Feng Zhou ◽  
Rui-Fu Yang ◽  
...  

2018 ◽  
Vol 10 (22) ◽  
pp. 2629-2635 ◽  
Author(s):  
Xiping Cui ◽  
Qiyi He ◽  
Ding Shen ◽  
Zhengyun Jiang ◽  
Yingshan Chen ◽  
...  

One-step enzyme-linked immunosorbent assay for glycocholic acid based on single-chain variable fragment-alkaline phosphatase fusion protein.


2020 ◽  
Vol 21 (8) ◽  
pp. 2999
Author(s):  
Sebastian W. Meister ◽  
Linnea C. Hjelm ◽  
Melanie Dannemeyer ◽  
Hanna Tegel ◽  
Hanna Lindberg ◽  
...  

The use of biotherapeutics for the treatment of diseases of the central nervous system (CNS) is typically impeded by insufficient transport across the blood–brain barrier. Here, we investigate a strategy to potentially increase the uptake into the CNS of an affibody molecule (ZSYM73) via binding to the transferrin receptor (TfR). ZSYM73 binds monomeric amyloid beta, a peptide involved in Alzheimer’s disease pathogenesis, with subnanomolar affinity. We generated a tri-specific fusion protein by genetically linking a single-chain variable fragment of the TfR-binding antibody 8D3 and an albumin-binding domain to the affibody molecule ZSYM73. Simultaneous tri-specific target engagement was confirmed in a biosensor experiment and the affinity for murine TfR was determined to 5 nM. Blockable binding to TfR on endothelial cells was demonstrated using flow cytometry and in a preclinical study we observed increased uptake of the tri-specific fusion protein into the cerebrospinal fluid 24 h after injection.


1989 ◽  
Vol 35 (12) ◽  
pp. 2319-2321 ◽  
Author(s):  
G H Thorpe ◽  
I Bronstein ◽  
L J Kricka ◽  
B Edwards ◽  
J C Voyta

Abstract We have evaluated a new chemiluminescent substrate for the alkaline phosphatase (EC 3.1.3.1) label used in a Hybritech Tandem-E immunoassay of alpha-fetoprotein (AFP). The new substrate, adamantyl 1,2-dioxetane phenyl phosphate (AMPPD), emits light at 477 nm when acted upon by the enzyme. Detection limits for AFP with this method were 33 ng/L (mean of 20 replicates of the zero standard + 2 SD) and 470 ng/L (twice background). Between-batch CVs ranged from 4.31% to 9.60% for AFP in the range 29.1-132.0 micrograms/L. Comparison of results for 49 specimens assayed with use of the chemiluminescent kit and a colorimetric version of the AFP assay gave statistical values as follows: slope = 0.88, intercept = 4.19, and r = 0.94.


2013 ◽  
Vol 405 (23) ◽  
pp. 7477-7484 ◽  
Author(s):  
Xiaoqi Tao ◽  
Min Chen ◽  
Haiyang Jiang ◽  
Jianzhong Shen ◽  
Zhanhui Wang ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2905
Author(s):  
Yoshiro Hanyu ◽  
Mieko Kato

Screening antibody libraries is an important step in establishing recombinant monoclonal antibodies. The colony assay can identify positive clones without almost any false-positives; however, its antibody library is smaller than those used in other recombinant screening methods such as phage display. Thus, to improve the efficiency of colony assays, it is necessary to increase library size per screening. Here, we report developing a colony assay with single-chain variable fragment (scFv) fused to the N-terminus of bacterial alkaline phosphatase (scFv-PhoA). The scFv-PhoA library was constructed in an expression vector specifically designed for this study. Use of this library allowed the successful and direct detection of positive clones exhibiting PhoA activity, without the need for a secondary antibody. Colony assay screening with scFv-PhoA is simple, rapid, offers a higher success rate than previous methods based on scFv libraries, and—most importantly—it enables high-throughput procedures.


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