Development of an accurate and cost-effective quantitative detection method for specific gene sequences

Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory system, as seen in various illnesses and conditions, such as cancer, autoimmunity, neurodegeneration and other physiological disorders. Cancer and autoimmune diseases are particularly adept at developing mechanisms to escape and modulate the immune system checkpoints, reflected by an altered cytokine profile. Cytokine profiling can provide valuable information for diagnosing such diseases and monitoring their progression, as well as assessing the efficacy of immunotherapeutic regiments. Toward this goal, there has been immense interest in the development of ultrasensitive quantitative detection techniques for cytokines, which involves technologies from various scientific disciplines, such as immunology, electrochemistry, photometry, nanotechnology and electronics. This review focusses on one aspect of this collective effort: electrochemical biosensors. Among the various types of biosensors available, electrochemical biosensors are one of the most reliable, user-friendly, easy to manufacture, cost-effective and versatile technologies that can yield results within a short period of time, making it extremely promising for routine clinical testing.

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Immobilization-Free Electrochemical Sensor Coupled with a Graphene-Oxide-Based Aptasensor for Glycated Albumin Detection

Biosensors ◽

10.3390/bios11030085 ◽

2021 ◽

Vol 11 (3) ◽

pp. 85

Author(s):

Wassa Waiwinya ◽

Thitirat Putnin ◽

Dechnarong Pimalai ◽

Wireeya Chawjiraphan ◽

Nuankanya Sathirapongsasuti ◽

...

Keyword(s):

Graphene Oxide ◽

Electrochemical Sensor ◽

Detection Method ◽

Limit Of Detection ◽

Glycated Albumin ◽

Cost Effective ◽

Logarithmic Scale ◽

Electrochemical Aptasensor ◽

Alternative Approach

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.

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A Rapid Quantitative Detection Method for Anaerobic Denitrifying Bacteria (ADNB)

2009 3rd International Conference on Bioinformatics and Biomedical Engineering ◽

10.1109/icbbe.2009.5162232 ◽

2009 ◽

Author(s):

Li Wei ◽

Jixian Yang ◽

Yanjun Wang ◽

Fang Ma ◽

Qiang Wang ◽

...

Keyword(s):

Detection Method ◽

Denitrifying Bacteria ◽

Quantitative Detection

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Comparative evaluation of cost effective extraction free molecular technique for detection of SARS-CoV-2 with reference to standard VTM based RT-qPCR method

Iranian Journal of Microbiology ◽

10.18502/ijm.v13i6.8073 ◽

2021 ◽

Author(s):

Megh Singh Dhakad ◽

Sanjib Gogoi ◽

Ansu Kumari ◽

Aashish Kumar Singh ◽

Manoj B. Jais ◽

...

Keyword(s):

Detection Method ◽

Cost Effective ◽

Molecular Technique ◽

Rt Pcr ◽

Index Method ◽

Resource Limited ◽

Qpcr Method ◽

Kappa Value ◽

The Cost ◽

Higher Sensitivity

Background and Objectives: The entire globe is undergoing an unprecedented challenge of COVID-19. Considering the need of rapid and accurate diagnostic tests for SARS-CoV-2, this study was planned to evaluate the cost effective extraction free RT-PCR technique in comparison to the standard VTM based RT-qPCR method. Materials and Methods: Paired swabs from nasopharynx and oropharynx were collected for SARS-CoV-2 testing, from 211 adult patients (≥18 years) in VTM and plain sterile tubes (dry swabs). These samples were processed and RT-qPCR was carried out as per standard protocols. Results: 54.5% of the patients were females and 45.5% were males with sex ratio 1:1.19 (M: F). 38.86% were symptomatic, of which fever (86.59%), cough (79.23%) and breathlessness (46.34%) were the most common symptoms. The positivity by VTM based method and index method was 31.27% and 13.27% respectively. Of the 27 inconclusive results from index method, 37.04% were positive, 48.15% were negative by VTM based method. However, in 40 inconclusive results by VTM based method, 90% were negative and rest remained inconclusive by index method. The sensitivity and specificity of the index method were 39.39% and 85.71% respectively. The overall agreement between VTM based method and index method was 49.59% with estimated Kappa value of 0.19. Conclusion: VTM based method showed higher sensitivity compared to the index method. The higher positivity by VTM based method, suggests that VTM based method could plausibly be a better detection method of SARS-CoV-2. Still, the index method might add value in a resource limited setups for detection of SARS-CoV-2.

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A Comparison of Antibacterial Activity of Selected Thyme (Thymus) Species by Means of the Dot Blot Test with Direct Bioautographic Detection

Journal of AOAC International ◽

10.5740/jaoacint.sge5-orlowska ◽

2015 ◽

Vol 98 (4) ◽

pp. 871-875 ◽

Cited By ~ 2

Author(s):

Marta Orłowska ◽

Teresa Kowalska ◽

Mieczysław Sajewicz ◽

Wioleta Jesionek ◽

Irena M Choma ◽

...

Keyword(s):

Antibacterial Activity ◽

Detection Method ◽

Cost Effective ◽

Polar Fraction ◽

Dot Blot ◽

Inhibition Zones ◽

Chromatographic Plate ◽

Direct Bioautography ◽

Bacterial Growth Inhibition ◽

Different Origin

Abstract Bioautography carried out with the aid of thin-layer chromatographic adsorbents can be used to assess antibacterial activity in samples of different origin. It can either be used as a simple and cost-effective detection method applied to a developed chromatogram, or to the dot blot test performed on a chromatographic plate, where total antibacterial activity of a sample is scrutinized. It was an aim of this study to compare antibacterial activity of 18 thyme (Thymus) specimens and species (originating from the same gardening plot and harvested in the same period of time) by means of a dot blot test with direct bioautography. A two-step extraction of herbal material was applied, and at step two the polar fraction of secondary metabolites was obtained under the earlier optimized extraction conditions [methanol–water (27 + 73, v/v), 130°C]. This fraction was then tested for its antibacterial activity against Bacillus subtilis bacteria. It was established that all investigated extracts exhibited antibacterial activity, yet distinct differences were perceived in the size of the bacterial growth inhibition zones among the compared thyme species. Based on the results obtained, T. citriodorus “golden dwarf” (sample No. 5) and T. marschallianus (sample No. 6) were selected as promising targets for further investigations and possible inclusion in a herbal pharmacopeia, which is an essential scientific novelty of this study.

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