IQPA: Isothermal nucleic acid amplification-based immunoassay using DNAzyme as the reporter system

Loh, Qiuting; Omar, Noorsharmimi; Glökler, Jörn; Lim, Theam Soon

doi:10.1016/j.ab.2014.06.012

Cited by 10 publications

(6 citation statements)

References 10 publications

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“…The potential of QPA was also explored to amplify an intrinsic quadruplex sequence that can act at the same time as a DNazyme reporter. By comparison, it was found that the classical hemin aptamer sequence outperformed the QPA quadruplex sequence to yield a better product (see Figure 29(b)) (Loh et al 2014). Yet, a very efficient means to amplify antibodylinked DNA probes is RPA in the form of RPA-ELISA for food analysis (Santiago-Felipe et al 2014).…”

Section: Immunoassaysmentioning

confidence: 99%

Isothermal amplifications – a comprehensive review on current methods

Glökler

Lim

Ida

et al. 2021

Critical Reviews in Biochemistry and Molecular Biology

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The introduction of nucleic acid amplification techniques has revolutionized the field of medical diagnostics in the last decade. The advent of PCR catalyzed the increasing application of DNA, not just for molecular cloning but also for molecular based diagnostics. Since the introduction of PCR, a deeper understanding of molecular mechanisms and enzymes involved in DNA/RNA replication has spurred the development of novel methods devoid of temperature cycling. Isothermal amplification methods have since been introduced utilizing different mechanisms, enzymes, and conditions. The ease with which isothermal amplification methods have allowed nucleic acid amplification to be carried out has had a profound impact on the way molecular diagnostics are being designed after the turn of the millennium. With all the advantages isothermal amplification brings, the issues or complications surrounding each method are heterogeneous making it difficult to identify the best approach for an end-user. This review pays special attention to the various isothermal amplification methods by classifying them based on the mechanistic characteristics which include reaction formats, amplification information, promoter, strand break, and refolding mechanisms. We would also compare the efficiencies and usefulness of each method while highlighting the potential applications and detection methods involved. This review will serve as an overall outlook on the journey and development of isothermal amplification methods as a whole.

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Section: Immunoassaysmentioning

confidence: 99%

Isothermal amplifications – a comprehensive review on current methods

Glökler

Lim

Ida

et al. 2021

Critical Reviews in Biochemistry and Molecular Biology

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“…The peroxidase mimicking catalytic activity of G4 DNAzyme catalyzes the oxidation of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS 2− ) to produce a colorimetric change from a colorless solution to a visible blue-green product (see Figure 9). DNAzyme systems involving other substrates like luminol, 3,3′,5,5′-tetramethylbenzidine sulfate (TMB), 4-chloro-1-naphthol (4-CN) or scopoletin (Sc), in the presence of hydrogen peroxide (H 2 O 2 ) can also be used to produce colorimetric, electrochemical and fluorescence readouts [46,47,48,49,50,51]. However, colorimetric G4-hemin DNAzyme-based biosensors are utilized in diagnostics for its simplicity, fast analysis, low cost and most notably, the ability to detect target molecules visually.…”

Section: G-quadruplex-based Detection Systemmentioning

confidence: 99%

G-Quadruplexes as An Alternative Recognition Element in Disease-Related Target Sensing

et al. 2019

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G-quadruplexes are made up of guanine-rich RNA and DNA sequences capable of forming noncanonical nucleic acid secondary structures. The base-specific sterical configuration of G-quadruplexes allows the stacked G-tetrads to bind certain planar molecules like hemin (iron (III)-protoporphyrin IX) to regulate enzymatic-like functions such as peroxidase-mimicking activity, hence the use of the term DNAzyme/RNAzyme. This ability has been widely touted as a suitable substitute to conventional enzymatic reporter systems in diagnostics. This review will provide a brief overview of the G-quadruplex architecture as well as the many forms of reporter systems ranging from absorbance to luminescence readouts in various platforms. Furthermore, some challenges and improvements that have been introduced to improve the application of G-quadruplex in diagnostics will be highlighted. As the field of diagnostics has evolved to apply different detection systems, the need for alternative reporter systems such as G-quadruplexes is also paramount.

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“…Streptavidin can be sandwiched between the antigen and antibody DNA to form the binding for IQPA to work. The hemin molecules are then used complex with the amplified G-quad structures to catalyse the colour change of ABTS in the presence of hydrogen peroxide [100].…”

Section: Fusion With Dna Technology-dnazyme Probe System Immuno-pcr mentioning

confidence: 99%

Phage Display‐Derived Antibodies: Application of Recombinant Antibodies for Diagnostics

Ch’ng¹,

Choong²,

Lim³

2016

Proof and Concepts in Rapid Diagnostic Tests and Technologies

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Antibodies are produced by the human body in response towards infections as a means of protection. The in vivo production of antibodies by B-cells involves a series of intricate gene editing processes resulting in a highly diverse pool of antibodies. However, this diversity can be replicated in vitro using phage display. Phage display offers the potential to present the antibody phenotype together with the cloned genotype of the specific antibody in a single-phage particle. Antibodies are highly sought after for diagnostic applications owing to its specificity and affinity towards a target antigen. The advent of recombinant antibody (rAb) technology allows for a faster and more costeffective solution for antibody generation. It also provides diagnostic developers with the possibility to customize the antibodies. Antibodies have been utilized successfully in various diagnostic platforms ranging from standard immunoassays to lateral-flow assays, nanoparticles, microfluidics, DNA-integrated assays and others. The limitless application of antibodies in the field of diagnostics has made it a critical component in any diagnostic development platform. This chapter focuses on the processes involved in antibody discovery including the various forms of antibody libraries for phage display and panning processes. We also highlight some diagnostic platforms that apply recombinant antibodies.

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IQPA: Isothermal nucleic acid amplification-based immunoassay using DNAzyme as the reporter system

Cited by 10 publications

References 10 publications

Isothermal amplifications – a comprehensive review on current methods

Isothermal amplifications – a comprehensive review on current methods

G-Quadruplexes as An Alternative Recognition Element in Disease-Related Target Sensing

Phage Display‐Derived Antibodies: Application of Recombinant Antibodies for Diagnostics

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