scholarly journals A High-Throughput Single-Clone Phage Fluorescence Microwell Immunoassay and Laser-Driven Clonal Retrieval System

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 517
Author(s):  
Seohee Chang ◽  
Soohyun Kim ◽  
Jerome Han ◽  
Suji Ha ◽  
Hyunho Lee ◽  
...  
Keyword(s):  
High Throughput ◽  
Retrieval System ◽  
Low Cost ◽  
Therapeutic Antibodies ◽  
Amino Acid Residues ◽  
Single Chain ◽  
Scfv Library ◽  
Single Clone ◽  
Library Complexity ◽  
Lower Complexity

Phage display is one of the most frequently used platform technologies utilized to screen and select therapeutic antibodies, and has contributed to the development of more than 10 therapeutic antibodies used in the clinic. Despite advantages like efficiency and low cost, it has intrinsic technical limitations, such as the asymmetrical amplification of the library after each round of biopanning, which is regarded as a reason for it yielding a very limited number of antigen binders. In this study, we developed a high-throughput single-clonal screening system comprised of fluorescence immunoassays and a laser-driven clonal DNA retrieval system using microchip technology. Using this system, from a single-chain variable fragment (scFv) library displayed on phages with a complexity of 5.21 × 105 harboring random mutations at five amino acid residues, more than 70,000 clones—corresponding to ~14% of the library complexity—were screened, resulting in 78 antigen-reactive scFv sequences with mutations restricted to the randomized residues. Our results demonstrate that this system can significantly reduce the number of biopanning rounds, or even eliminate the need for this process for libraries with lower complexity, providing an opportunity to obtain more diverse clones from the library.

scholarly journals Construction and directional evolution of anti-enrofloxacin ScFv antibody for the immunoassay of fluoroquinolones

2021 ◽  
Author(s):  
Fangyu Wang ◽  
Ning Li ◽  
Yunshang Zhang ◽  
Xuxefeng Sun ◽  
Yali Zhao ◽  
...  
Keyword(s):  
Amino Acid ◽  
Scfv Antibody ◽  
Phage Library ◽  
Enzyme Linked Immunosorbent Assay ◽  
Amino Acid Residues ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Relative Standard ◽  
Directional Evolution ◽  
Scfv Library

Abstract A recombinant anti-enrofloxacin single-chain antibody (scFv) was produced for the detection of enrofloxacin. An immunized mouse phage display scFv library with a capacity of 2.35×109 CFU/mL was constructed and used for anti-enrofloxacin scFv screening. After four rounds of bio-panning, 10 positives were isolated and identified successfully. The highest positive scFv was expressed in E. coli BL21. Then, its recognition mechanisms were studied using the molecular docking method. The result showed the amino acid residues Leu121 were the key residues for the binding of ScFv to ENR. Based on the results of virtual mutation, the ScFv antibody was evolved by directional mutagenesis of contact amino acid residue Leu121 to Asn. After the expression and purification, an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) based on the parental and mutant ScFv were established for enrofloxacin respectively. The IC50 value of the assay established with the ScFv mutant was 1.63 ng/mL, while the parental ScFv was 21.08 ng/mL, this result showed highly increased affinity with up to 12.9-folds improved sensitivity. The mean recovery for ENR ranged from 71.80% to 117.35% with 10.46% relative standard deviation between the intra-assay and the inter-assay. The results indicate that we have obtained a highly sensitive anti-ENR scFv by the phage library construction and directional evolution, and the scFv-based IC-ELISA is suitable for the detection of ENR residue in animal derived edible tissues and milk.

scholarly journals High-throughput retrieval of physical DNA for NGS-identifiable clones in phage display library

2018 ◽  
Author(s):  
Jinsung Noh ◽  
Okju Kim ◽  
Yushin Jung ◽  
Haejun Han ◽  
Jung-Eun Kim ◽  
...  
Keyword(s):  
High Throughput ◽  
Antibody Fragment ◽  
Phage Display Library ◽  
Sequence Information ◽  
Single Chain ◽  
Depth Analysis ◽  
Scfv Library ◽  
Linkage Information ◽  
Antibody Discovery ◽  
Human Hepatocyte Growth Factor

AbstractIn antibody discovery, in-depth analysis of an antibody library and high-throughput retrieval of clones in the library are crucial to identifying and exploiting rare clones with different properties. However, existing methods have several technical limitations such as low process throughput from laborious cloning process and waste of the phenotypic screening capacity from unnecessary repetitive tests on the dominant clones. To overcome the limitations, we developed a new high-throughput platform for the identification and retrieval of clones in the library, TrueRepertoire™. TrueRepertoire™ provides highly accurate sequences of the clones with linkage information between heavy and light chains of the antibody fragment. Additionally, the physical DNA of clones can be retrieved in high throughput based on the sequence information. We validated the high accuracy of the sequences and demonstrated that there is no platform-specific bias. Moreover, the applicability of TrueRepertoire™ was demonstrated by a phage-displayed single-chain variable fragment (scFv) library targeting human hepatocyte growth factor (hHGF) protein.

scholarly journals Construction and directional evolution of anti-enrofloxacin ScFv antibody for the immunoassay of fluoroquinolones

2021 ◽  
Author(s):  
Guangxu Xing ◽  
Yunshang Zhang ◽  
Fangyu Wang ◽  
Liuding Wen ◽  
Gaiping Zhang
Keyword(s):  
Amino Acid ◽  
Scfv Antibody ◽  
Phage Library ◽  
Enzyme Linked Immunosorbent Assay ◽  
Amino Acid Residues ◽  
Single Chain ◽  
Single Chain Antibody ◽  
Relative Standard ◽  
Directional Evolution ◽  
Scfv Library

Abstract A recombinant anti-enrofloxacin single-chain antibody (scFv) was produced for the detection of enrofloxacin. An immunized mouse phage display scFv library with a capacity of 2.35×109 CFU/mL was constructed and used for anti-enrofloxacin scFv screening. After four rounds of bio-panning, 10 positives were isolated and identified successfully. The highest positive scFv was expressed in E. coli BL21. Then, its recognition mechanisms were studied using the molecular docking method. The result showed the amino acid residues Leu121 were the key residues for the binding of ScFv to ENR. Based on the results of virtual mutation, the ScFv antibody was evolved by directional mutagenesis of contact amino acid residue Leu121 to Asn. After the expression and purification, an indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) based on the parental and mutant ScFv were established for enrofloxacin respectively. The IC50 value of the assay established with the ScFv mutant was 1.63 ng/mL, while the parental ScFv was 21.08 ng/mL, this result showed highly increased affinity with up to 12.9-folds improved sensitivity. The mean recovery for ENR ranged from 71.80% to 117.35% with 10.46% relative standard deviation between the intra-assay and the inter-assay. The results indicate that we have obtained a highly sensitive anti-ENR scFv by the phage library construction and directional evolution, and the scFv-based IC-ELISA is suitable for the detection of ENR residue in animal derived edible tissues and milk.

scholarly journals Organ-specific, multimodal, wireless optoelectronics for high-throughput phenotyping of peripheral neural pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  
Keyword(s):  
High Throughput ◽  
Low Cost ◽  
Optoelectronic Device ◽  
Antenna System ◽  
Neural Pathways ◽  
Organ Specific ◽  
Coil Antenna ◽  
Sensory Fibers

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.

scholarly journals Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu
Keyword(s):  
Diffusion Couple ◽  
Titanium Alloys ◽  
High Throughput ◽  
Volume Fraction ◽  
Raw Materials ◽  
Low Cost ◽  
High Strength ◽  
High Yield ◽  
Α Phase ◽  
Cr System

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.

scholarly journals Structural Analysis of Yoked Chorionic Gonadotropin-Luteinizing Hormone Receptor Ectodomain Complexes by Circular Dichroic Spectroscopy

2003 ◽  
Vol 17 (7) ◽  
pp. 1192-1202 ◽  
Author(s):  
Gregory B. Fralish ◽  
Brian Dattilo ◽  
David Puett
Keyword(s):  
Chorionic Gonadotropin ◽  
Fusion Proteins ◽  
Homology Model ◽  
Difference Spectrum ◽  
Luteinizing Hormone Receptor ◽  
Amino Acid Residues ◽  
Single Chain ◽  
Glycoprotein Hormone ◽  
The Difference ◽  
Α Helix

Abstract Binding of the heterodimeric glycoprotein hormone, chorionic gonadotropin (CG), occurs to the heptahelical LH receptor N-terminal ectodomain (ECD), a large portion of which has been modeled as a leucine-rich repeat protein. In this study, we expressed and purified three single chain N-CG-ECD-C complexes, one comprising the full-length ECD, 1–341 (encoded by exons 1–10 and a portion of 11), and two C-terminal ECD deletion fragments, 1–294 (encoded by exons 1–10) and 1–180 (encoded by exons 1–7). The fusion proteins, including yoked CG (N-β-α-C), were characterized by Western blot analysis and circular dichroism (CD). Analysis of the CD spectra obtained on the CG-ECD fusion proteins, and of the difference spectrum of each after subtracting the CG contribution, yielded secondary structures consistent with a repeating β-strand/α-helix fold as predicted in the homology model. A marked decrease in helicity was observed when the C-terminal 47 amino acid residues were removed from the ECD. Removal of an additional 114 residues, i.e. the region encoded by exons 8–10, results in the loss of fewer helical residues. These results suggest that the hinge region of the ECD, predicted to contain only limited secondary structure, interacts with and stabilizes the ligand-occupied N-terminal portion. Furthermore, the results support a repeating fold, consistent with the proposed model for the LHR ECD.

Efficient High-throughput Techniques for the Analysis of Disease-Resistant Plant Varieties and Detection of Food Adulteration

2021 ◽  
Vol 23 ◽  
Author(s):  
Romesh Kumar Salgotra ◽  
Rafiq Ahmad Bhat ◽  
Deyue Yu ◽  
Javaid Akhter Bhat
Keyword(s):  
Multiplex Pcr ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Low Cost ◽  
Crop Improvement ◽  
Small Sample ◽  
Food Crops ◽  
Genomic Resources ◽  
Breeding Programmes ◽  
Next Generation Sequencing Ngs

Abstract: Over the past two decades, the advances in the next generation sequencing (NGS) platforms have led to the identification of numerous genes/QTLs at high-resolution for their potential use in crop improvement. The genomic resources generated through these high-throughput sequencing techniques have been efficiently used in screening of particular gene of interest particularly for numerous types of plant stresses and quality traits. Subsequently, the identified-markers linked to a particular trait have been used in marker-assisted backcross breeding (MABB) activities. Besides, these markers are also being used to catalogue the food crops for detection of adulteration to improve the quality of food. With the advancement of technologies, the genomic resources are originating with new markers; however, to use these markers efficiently in crop breeding, high-throughput techniques (HTT) such as multiplex PCR and capillary electrophoresis (CE) can be exploited. Robustness, ease of operation, good reproducibility and low cost are the main advantages of multiplex PCR and CE. The CE is capable of separating and characterizing proteins with simplicity, speed and small sample requirements. Keeping in view the availability of vast data generated through NGS techniques and development of numerous markers, there is a need to use these resources efficiently in crop improvement programmes. In summary, this review describes the use of molecular markers in the screening of resistance genes in breeding programmes and detection of adulterations in food crops using high-throughput techniques.

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