scholarly journals Advances in Directly Amplifying Nucleic Acids from Complex Samples

Biosensors ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 117 ◽  
Author(s):  
Faye M. Walker ◽  
Kuangwen Hsieh
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Point Of Care ◽  
Nucleic Acid Amplification ◽  
Current Status ◽  
Diagnostic Tools ◽  
Complex Samples ◽  
Lab On Chip ◽  
On Chip ◽  
Effective Visualization

Advances in nucleic acid amplification technologies have revolutionized diagnostics for systemic, inherited, and infectious diseases. Current assays and platforms, however, often require lengthy experimental procedures and multiple instruments to remove contaminants and inhibitors from clinically-relevant, complex samples. This requirement of sample preparation has been a bottleneck for using nucleic acid amplification tests (NAATs) at the point of care (POC), though advances in “lab-on-chip” platforms that integrate sample preparation and NAATs have made great strides in this space. Alternatively, direct NAATs—techniques that minimize or even bypass sample preparation—present promising strategies for developing POC diagnostic tools for analyzing real-world samples. In this review, we discuss the current status of direct NAATs. Specifically, we surveyed potential testing systems published from 1989 to 2017, and analyzed their performances in terms of robustness, sensitivity, clinical relevance, and suitability for POC diagnostics. We introduce bubble plots to facilitate our analysis, as bubble plots enable effective visualization of the performances of these direct NAATs. Through our review, we hope to initiate an in-depth examination of direct NAATs and their potential for realizing POC diagnostics, and ultimately transformative technologies that can further enhance healthcare.

A Review of Design Considerations for Hemocompatibility within Microfluidic Systems

2020 ◽  
Vol 46 (05) ◽  
pp. 622-636
Author(s):  
Crispin Szydzik ◽  
Rose J. Brazilek ◽  
Warwick S. Nesbitt
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Diagnostic Tools ◽  
Microfluidic Systems ◽  
Experimental Conditions ◽  
Lab On Chip ◽  
Design Considerations ◽  
Chip Technology ◽  
On Chip

AbstractThe manipulation of blood within in vitro environments presents a persistent challenge, due to the highly reactive nature of blood, and its multifaceted response to material contact, changes in environmental conditions, and stimulation during handling. Microfluidic Lab-on-Chip systems offer the promise of robust point-of-care diagnostic tools and sophisticated research platforms. The capacity for precise control of environmental and experimental conditions afforded by microfluidic technologies presents unique opportunities that are particularly relevant to research and clinical applications requiring the controlled manipulation of blood. A critical bottleneck impeding the translation of existing Lab-on-Chip technology from laboratory bench to the clinic is the ability to reliably handle relatively small blood samples without negatively impacting blood composition or function. This review explores design considerations critical to the development of microfluidic systems intended for use with whole blood from an engineering perspective. Material hemocompatibility is briefly explored, encompassing common microfluidic device materials, as well as surface modification strategies intended to improve hemocompatibility. Operational hemocompatibility, including shear-induced effects, temperature dependence, and gas interactions are explored, microfluidic sample preparation methodologies are introduced, as well as current techniques for on-chip manipulation of the whole blood. Finally, methods of assessing hemocompatibility are briefly introduced, with an emphasis on primary hemostasis and platelet function.

scholarly journals Laboratory Diagnostic Tools for Syphilis: Current Status and Future Prospects

2021 ◽  
Vol 10 ◽  
Author(s):  
Yuting Luo ◽  
Yafeng Xie ◽  
Yongjian Xiao
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Amplification ◽  
Detection Methods ◽  
Current Status ◽  
Morphological Observation ◽  
Diagnostic Tools ◽  
Clinical Samples ◽  
Serologic Tests ◽  
Number Of Patients ◽  
Infectivity Test

With the increasing number of patients infected with syphilis in the past 20 years, early diagnosis and early treatment are essential to decline syphilis prevalence. Owing to its diverse manifestations, which may occur in other infections, the disease often makes clinicians confused. Therefore, a sensitive method for detecting T. pallidum is fundamental for the prompt diagnosis of syphilis. Morphological observation, immunohistochemical assay, rabbit infectivity test, serologic tests, and nucleic acid amplification assays have been applied to the diagnosis of syphilis. Morphological observation, including dark-field microscopy, silver-staining, and direct fluorescent antibody staining for T. pallidum, can be used as a direct detection method for chancre specimens in primary syphilis. Immunohistochemistry is a highly sensitive and specific assay, especially in the lesion biopsies from secondary syphilis. Rabbit infectivity test is considered as a sensitive and reliable method for detecting T. pallidum in clinical samples and used as a historical standard for the diagnosis of syphilis. Serologic tests for syphilis are widely adopted using non-treponemal or treponemal tests by either the traditional or reverse algorithm and remain the gold standard in the diagnosis of syphilis patients. In addition, nucleic acid amplification assay is capable of detecting T. pallidum DNA in the samples from patients with syphilis. Notably, PCR is probably a promising method but remains to be further improved. All of the methods mentioned above play important roles in various stages of syphilis. This review aims to provide a summary of the performance characteristics of detection methods for syphilis.

Implementation of antimicrobial peptides for sample preparation prior to nucleic acid amplification in point-of-care settings

2017 ◽  
Vol 17 (12) ◽  
pp. 1117-1125
Author(s):  
Katrin Krõlov ◽  
Julia Uusna ◽  
Tiia Grellier ◽  
Liis Andresen ◽  
Jekaterina Jevtuševskaja ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Antimicrobial Peptides ◽  
Point Of Care ◽  
Nucleic Acid Amplification

scholarly journals Quantitative and rapid Plasmodium falciparum malaria diagnosis and artemisinin-resistance detection using a CMOS Lab-on-Chip platform

2019 ◽  
Author(s):  
K. Malpartida-Cardenas ◽  
N. Miscourides ◽  
J. Rodriguez-Manzano ◽  
L. S. Yu ◽  
J. Baum ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Point Of Care ◽  
Artemisinin Resistance ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
Optical Measurements ◽  
Oxide Semiconductor ◽  
Analytical Sensitivity ◽  
Lab On Chip ◽  
On Chip

AbstractEarly and accurate diagnosis of malaria and drug-resistance is essential to effective disease management. Available rapid malaria diagnostic tests present limitations in analytical sensitivity, drug-resistant testing and/or quantification. Conversely, diagnostic methods based on nucleic acid amplification stepped forwards owing to their high sensitivity, specificity and robustness. Nevertheless, these methods commonly rely on optical measurements and complex instrumentation which limit their applicability in resource-poor, point-of-care settings. This paper reports the specific, quantitative and fully-electronic detection of Plas-modium falciparum, the predominant malaria-causing parasite worldwide, using a Lab-on-Chip platform developed in-house. Furthermore, we demonstrate on-chip detection of C580Y, the most prevalent single-nucleotide polymorphism associated to artemisinin-resistant malaria. Real-time non-optical DNA sensing is facilitated using Ion-Sensitive Field-Effect Transistors, fabricated in unmodified complementary metal-oxide-semiconductor technology, coupled with loop-mediated isothermal amplification. This work holds significant potential for the development of a fully portable and quantitative malaria diagnostic that can be used as a rapid point-of-care test.

scholarly journals Nitrocellulose-bound achromopeptidase for point-of-care nucleic acid tests

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Georgios Chondrogiannis ◽  
Shirin Khaliliazar ◽  
Anna Toldrà ◽  
Pedro Réu ◽  
Mahiar M. Hamedi
Keyword(s):  
Nucleic Acid ◽  
Sample Preparation ◽  
Point Of Care ◽  
Dna Amplification ◽  
Recombinase Polymerase Amplification ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Enzymatic Function ◽  
Modern Biotechnology ◽  
Nucleic Acid Tests

AbstractEnzymes are the cornerstone of modern biotechnology. Achromopeptidase (ACP) is a well-known enzyme that hydrolyzes a number of proteins, notably proteins on the surface of Gram-positive bacteria. It is therefore used for sample preparation in nucleic acid tests. However, ACP inhibits DNA amplification which makes its integration difficult. Heat is commonly used to inactivate ACP, but it can be challenging to integrate heating into point-of-care devices. Here, we use recombinase polymerase amplification (RPA) together with ACP, and show that when ACP is immobilized on nitrocellulose paper, it retains its enzymatic function and can easily and rapidly be activated using agitation. The nitrocellulose-bound ACP does, however, not leak into the solution, preventing the need for deactivation through heat or by other means. Nitrocellulose-bound ACP thus opens new possibilities for paper-based Point-of-Care (POC) devices.

Point-of-Care Systems for Rapid DNA Quantification in Oncology

2008 ◽  
Vol 94 (2) ◽  
pp. 216-225 ◽  
Author(s):  
Marco Bianchessi ◽  
Sarah Burgarella ◽  
Marco Cereda
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Semiconductor Industry ◽  
Point Of Care Testing ◽  
Lab On Chip ◽  
Diagnostic Assays ◽  
Care Systems ◽  
Point Of Care Systems ◽  
The Common ◽  
On Chip

The development of new powerful applications and the improvement in fabrication techniques are promising an explosive growth in lab-on-chip use in the upcoming future. As the demand reaches significant levels, the semiconductor industry may enter in the field, bringing its capability to produce complex devices in large volumes, high quality and low cost. The lab-on-chip concept, when applied to medicine, leads to the point-of-care concept, where simple, compact and cheap instruments allow diagnostic assays to be performed quickly by untrained personnel directly at the patient's side. In this paper, some practical and economical considerations are made to support the advantages of point-of-care testing. A series of promising technologies developed by STMicroelectronics on lab-on-chips is also presented, mature enough to enter in the common medical practice. The possible use of these techniques for cancer research, diagnosis and treatment are illustrated together with the benefits offered by their implementation in point-of-care testing.

Long-term dry storage of enzyme-based reagents for isothermal nucleic acid amplification in a porous matrix for use in point-of-care diagnostic devices

The Analyst ◽  
2020 ◽  
Vol 145 (21) ◽  
pp. 6875-6886 ◽  
Author(s):  
Sujatha Kumar ◽  
Ryan Gallagher ◽  
Josh Bishop ◽  
Enos Kline ◽  
Joshua Buser ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Glass Fiber ◽  
Point Of Care ◽  
Porous Matrix ◽  
Isothermal Amplification ◽  
Nucleic Acid Amplification ◽  
Isothermal Nucleic Acid Amplification ◽  
Dry Storage

Long-term dry storage of enzyme-based isothermal amplification reagents in glass fiber porous matrix for use in point-of-care devices.

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