Single-Molecule Detection of Specific Nucleic Acid Sequences in Unamplified Genomic DNA

1997 ◽  
Vol 69 (19) ◽  
pp. 3915-3920 ◽  
Author(s):  
Alonso Castro ◽  
John G. K. Williams
Keyword(s):  
Nucleic Acid ◽  
Single Molecule ◽  
Genomic Dna ◽  
Single Molecule Detection ◽  
Nucleic Acid Sequences

Fast high-resolution mapping of long fragments of genomic DNA based on single-molecule detection

2010 ◽  
Vol 402 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Ekaterina Protozanova ◽  
Meng Zhang ◽  
Eric J. White ◽  
Emilia T. Mollova ◽  
Dirk Ten Broeck ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Molecule ◽  
Genomic Dna ◽  
Single Molecule Detection ◽  
High Resolution Mapping ◽  
Resolution Mapping

Single Molecule Detection of Fluorescently Labelled DNA Dendrimers

2000 ◽  
Vol 6 (S2) ◽  
pp. 856-857
Author(s):  
TW Nilsen ◽  
R. Getts ◽  
M. Weinstein
Keyword(s):  
Nucleic Acid ◽  
Fluorescence Microscopy ◽  
Western Blot ◽  
Single Molecule ◽  
Point Sources ◽  
Nucleic Acid Hybridization ◽  
Single Molecule Detection ◽  
Underlying Principle ◽  
Microscopic Techniques

Single molecule detection has been achieved via many highly sophisticated microscopic techniques. Here we describe the detection of single molecules with conventional epifluorescent microscopy. The key to the technique is the use of DNA dendrimers DNA dendrimers have demonstrated utility in nucleic acid blots, Southerns, Northerns, etc. Typically DNA dendrimers yield 50-100 fold gain in signal over comparably labeled oligonucleotides. Immunodendrimers, DNA dendrimers conjugated to antibody molecules, have also been constructed and utilized in western blot assays. Individual, i.e. single molecule, 4- layer dendrimers, are readily detectable as point sources via conventional fluorescence microscopy and are useful for in situ hybridization and flow fluorescence quantitation.Nucleic acid hybridization is the underlying principle behind DNA dendrimer assembly. The “monomer” of DNA dendrimers consists of partially double stranded heteroduplexed DNA. Each monomer has an approximately 50 base double stranded “waist” surrounded by four approximately 30 base single stranded “arms”.

Gold-Aptamer-Nanoconstructs Engineered to Detect Conserved Enteroviral Nucleic Acid Sequences

2019 ◽  
Author(s):  
Veeren Chauhan ◽  
Mohamed M Elsutohy ◽  
C Patrick McClure ◽  
Will Irving ◽  
Neil Roddis ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
In Silico ◽  
Point Of Care ◽  
Lateral Flow ◽  
Nucleic Acid Sequence ◽  
In Silico Screening ◽  
Lateral Flow Assays ◽  
Life Threatening ◽  
Software And Hardware ◽  
Nucleic Acid Sequences

<p>Enteroviruses are a ubiquitous mammalian pathogen that can produce mild to life-threatening disease. Bearing this in mind, we have developed a rapid, accurate and economical point-of-care biosensor that can detect a nucleic acid sequences conserved amongst 96% of all known enteroviruses. The biosensor harnesses the physicochemical properties of gold nanoparticles and aptamers to provide colourimetric, spectroscopic and lateral flow-based identification of an exclusive enteroviral RNA sequence (23 bases), which was identified through in silico screening. Aptamers were designed to demonstrate specific complementarity towards the target enteroviral RNA to produce aggregated gold-aptamer nanoconstructs. Conserved target enteroviral nucleic acid sequence (≥ 1x10<sup>-7</sup> M, ≥1.4×10<sup>-14</sup> g/mL), initiates gold-aptamer-nanoconstructs disaggregation and a signal transduction mechanism, producing a colourimetric and spectroscopic blueshift (544 nm (purple) > 524 nm (red)). Furthermore, lateral-flow-assays that utilise gold-aptamer-nanoconstructs were unaffected by contaminating human genomic DNA, demonstrated rapid detection of conserved target enteroviral nucleic acid sequence (< 60 s) and could be interpreted with a bespoke software and hardware electronic interface. We anticipate our methodology will translate in-silico screening of nucleic acid databases to a tangible enteroviral desktop detector, which could be readily translated to related organisms. This will pave-the-way forward in the clinical evaluation of disease and complement existing strategies at overcoming antimicrobial resistance.</p>

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