scholarly journals SaQuant: a real-time PCR assay for quantitative assessment of Staphylococcus aureus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Colin Wood ◽  
Jason Sahl ◽  
Sara Maltinsky ◽  
Briana Coyne ◽  
Benjamin Russakoff ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Pathogen Detection ◽  
Limit Of Detection ◽  
Future Research ◽  
Limit Of Quantification ◽  
Pathogen Prevalence ◽  
Single Well ◽  
Effective Public Health ◽  
Detection And Quantification

Abstract Background Molecular assays are important tools for pathogen detection but need to be periodically re-evaluated with the discovery of additional genetic diversity that may cause assays to exclude target taxa or include non-target taxa. A single well-developed assay can find broad application across research, clinical, and industrial settings. Pathogen prevalence within a population is estimated using such assays and accurate results are critical for formulating effective public health policies and guiding future research. A variety of assays for the detection of Staphylococcus aureus are currently available. The utility of commercial assays for research is limited, given proprietary signatures and lack of transparent validation. Results In silico testing of existing peer-reviewed assays show that most suffer from a lack of sensitivity and specificity. We found no assays that were specifically designed and validated for quantitative use. Here we present a qPCR assay, SaQuant, for the detection and quantification of S. aureus as might be collected on sampling swabs. Sensitivity and specificity of the assay was 95.6 and 99.9 %, respectively, with a limit of detection of between 3 and 5 genome equivalents and a limit of quantification of 8.27 genome equivalents. The presence of DNA from non-target species likely to be found in a swab sample, did not impact qualitative or quantitative abilities of the assay. Conclusions This assay has the potential to serve as a valuable tool for the accurate detection and quantification of S. aureus collected from human body sites in order to better understand the dynamics of prevalence and transmission in community settings.

scholarly journals Development and Validation of a GC-MS Method for the Detection and Quantification of Clotiapine in Blood and Urine Specimens and Application to a Postmortem Case

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giulio Mannocchi ◽  
Flaminia Pantano ◽  
Roberta Tittarelli ◽  
Miriam Catanese ◽  
Federica Umani Ronchi ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Published Data ◽  
Limit Of Quantification ◽  
Blood And Urine Samples ◽  
Development And Validation ◽  
Urine Specimens ◽  
Detection And Quantification

Introduction. Clotiapine is an atypical antipsychotic of the dibenzothiazepine class introduced in a few European countries since 1970, efficient in treatment-resistant schizophrenic patients. There is little published data on the therapeutic and toxic concentrations of this drug.Aims. The aim of the present study is the development and validation of a method that allows the detection and quantification of clotiapine in blood and urine specimens by gas chromatography-mass spectrometry (GC-MS).Methods. Validation was performed working on spiked postmortem blood and urine samples. Samples were extracted with liquid-liquid extraction (LLE) technique at pH 8.5 with n-hexane/dichloromethane (85/15 v/v) and analysis was followed by GC-MS. Methadone-d9 was used as internal standard.Results. The limit of detection (LOD) was 1.2 and 1.3 ng/mL for urine and blood, respectively, while the lower limit of quantification (LLOQ) was 3.9 and 4.3 ng/mL, respectively. Linearity, precision, selectivity, accuracy, and recovery were also determined. The method was applied to a postmortem case. The blood and urine clotiapine concentrations were 1.32 and 0.49 μg/mL, respectively.Conclusions. A reliable GC-MS method for the detection and quantification of clotiapine in blood and urine samples has been developed and fully validated and then applied to a postmortem case.

scholarly journals Development of a Sensitive Real-Time Fast-qPCR Based on SYBR® Green for Detection and Quantification of Chicken Parvovirus (ChPV)

2018 ◽  
Vol 5 (3) ◽  
pp. 69 ◽  
Author(s):  
Luis Nuñez ◽  
Silvana Santander-Parra ◽  
Lucas Chaible ◽  
David De la Torre ◽  
Marcos Buim ◽  
...  
Keyword(s):  
Real Time ◽  
Viral Infections ◽  
Limit Of Detection ◽  
Melting Curve ◽  
Clinical Signs ◽  
Limit Of Quantification ◽  
Viral Genomes ◽  
Standard Curve ◽  
Ns Gene ◽  
Detection And Quantification

Many viruses have been associated with runting and stunting syndrome (RSS). These viral infections mainly affect young chickens, causing apathy, depression, ruffled feathers, cloacal pasting, and diarrhea. Chicken Parvovirus (ChPV) is such an infection and has been detected in chickens showing signs of enteric diseases worldwide. Therefore, the present study aims to develop a sensitive real-time fast-qPCR assay based on SYBR® Green for detection and quantification of ChPV. A 561-bp non-structural (NS) gene was amplified and cloned, and a pair of primers was designed based on conserved nucleotide sequences on the NS gene of ChPV, the intercalating DNA reagent SYBR® Green was employed, and the Fast mode of a thermocycler was used. The assay detects 109 to 101 copies of the genome (CG). The limit of detection (LoD) was estimated to five CG, and the limit of quantification (LoQ) was estimated at ten CG. The standard curve efficiency was 101.94%, and the melting curve showed a unique clean peak and a melting temperature of 79.3 °C. The assay was specific to amplify the ChPV NS gene, and no amplification was shown from other viral genomes or in the negative controls. A total of 141 samples were tested using the assay, of which 139 samples were found positive. The highest CG value of ChPV was 5.7 × 106 CG/uL of DNA without apparent clinical signs of enteric disturbance, and 4.6 × 106 CG/uL DNA were detected in chickens with RSS.

scholarly journals Validated UV-Vis Spectrophotometric Determination of Andrographolide in Herbal Nano-Preparation

2019 ◽  
Vol 31 (9) ◽  
pp. 1985-1988
Author(s):  
Indah Hairunisa ◽  
Muhammad Da'i ◽  
Erindyah Retno Wikantyasning ◽  
Andhika Rizky Gilang Mahaputra ◽  
Normaidah Normaidah ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Picric Acid ◽  
Limit Of Quantification ◽  
Intermediate Precision ◽  
Herbal Products ◽  
Relative Standard ◽  
Acid Reagent ◽  
Interday Precision ◽  
Detection And Quantification

Determination of major bioactive compounds in polyphyto-formulation is important for production of standardized herbal products. A fast, simple and inexpensive method for detection and quantification of andrographolide concentration in nanoemulsion preparations containing a combination of Andrographis paniculata (Burm f.) Ness. and Phyllanthus niruri L. has been developed. Detection and quantification were carried out using UV-vis spectrophotometry analysis with picric acid reagent and NaOH (8:2) in methanol solvents, read at maximum wavelength 479 nm with 22 min of incubation time. Validation was done by determine the parameters such as linearity, intra and interday precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). The results obtained showed linearity with r = 0.9945 (y = 0.0109x − 0.2066) in the range of 30-80 μg/mL. The accuracy (recovery) varied in the range of 97.15 to 104.42 %. Percentage of relative standard deviation (% RSD) for precision and intermediate precision value were 3.23 and 3.02 % with LOD value 211 μg/mL and the LOQ 705 μg/mL. As a conclusion, this method is suitable to detect andrographolide content in herbal nano-preparation.

scholarly journals A Low-Cost, 3D-Printed Biosensor for Rapid Detection of Escherichia coli

2022 ◽  
Author(s):  
Samir Malhotra ◽  
Dang Song Pham ◽  
Michael P.H. Lau ◽  
Anh H. Nguyen ◽  
Hung Cao
Keyword(s):  
Escherichia Coli ◽  
Rapid Detection ◽  
Pathogen Detection ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Bacterial Pathogens ◽  
Cross Reactivity ◽  
Potential Candidate ◽  
Limit Of Quantification ◽  
3D Printed

Detection of bacterial pathogens is significant in the fields of food safety, medicine, public health, etc. If bacterial pathogens are not treated promptly, antimicrobial resistance is possible and can lead to morbidity and mortality. Current bacterial detection methodologies rely on laboratory-based techniques that pose limitations such as long turnaround detection times, expensive costs, in-adequate accuracy, and required trained specialists. Here, we describe a cost-effective and port-able 3D-printed electrochemical biosensor that facilitates rapid detection of certain Escherichia coli (E. coli) strains (DH5α, BL21, TOP10, and JM109) within 15 minutes using 500 μL of sample and costs $2.50 per test. The sensor displayed an excellent limit of detection (LOD) of 53 CFU, limit of quantification (LOQ) of 270 CFU, and showed cross-reactivity with strains BL21 and JM109 due to shared epitopes. This advantageous diagnostic device is a potential candidate for high-frequency testing at the point of care as well as applicable to various fields where pathogen detection is of interest.

scholarly journals Determination of the limit of quantification of the calorimeter using a mixture of benzoic acid and silicon dioxide

2011 ◽  
Vol 65 (1) ◽  
pp. 93-97
Author(s):  
Vesna Krstic ◽  
Branko Blagojevic ◽  
Lidija Gomidzelovic ◽  
Emina Pozega ◽  
Jelena Petrovic ◽  
...  
Keyword(s):  
Quality Control ◽  
Benzoic Acid ◽  
Silicon Dioxide ◽  
Limit Of Detection ◽  
Certified Reference Materials ◽  
Laboratory Work ◽  
Measuring Range ◽  
Limit Of Quantification ◽  
Detection And Quantification

In recent years quality control has received a great attention in laboratory work. Implementation of the international standard ISO/IEC 17025 is necessary for any laboratory that wishes to establish quality control in its work. One of the important factors for meeting the requirements of this standard is the usage of the certified reference materials (CRM) in laboratory work. In order to determine the performance of the calorimeter, benzoic acid as CRM, from AlliedSignal Riedelda Haen, Ref.: 33045 and SiO2, Pro analyze, in various mass ratios was used. The results showed that benzoic acid can be successfully utilized for the control of the entire technical and instrumental measuring range and resolve the problem of determination of the limit of detection and quantification of the calorimeter.

scholarly journals Quantification of retinyl palmitate, thiamine, niacin, pyridoxine, folic acid, cyanocobalamin, zinc, and iron by chromatographic methods in fortified kernels and fortified rice

2020 ◽  
Author(s):  
Elise Ivarsen ◽  
Christoffer P. Andersen ◽  
Sabine M. Jensen ◽  
Carsten T. Pedersen ◽  
Anders K. Svaneborg
Keyword(s):  
Folic Acid ◽  
Standard Deviation ◽  
Limit Of Detection ◽  
Retinyl Palmitate ◽  
Good Resolution ◽  
Icp Oes ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Analyte Content ◽  
Detection And Quantification

AbstractThis study presents the optimization and validation of methods for the analysis of retinol, thiamine, niacin, pyridoxine, folic acid, cyanocobalamin, zinc, and iron in fortified kernels (coated and extruded) and in fortified rice. The analyses were performed by HPLC-UV/FLD/MS and ICP-OES. The optimized methods showed good resolution of the analyte peaks, excellent recovery (87–108%), reproducibility with relative standard deviation (SD) of analyte content between 1.8 and 11% and high correlation coefficient of the calibration curves (R2 > 0.997). Limit of detection was from 2.8 E-4 mg/kg for pyridoxine to 1.26 mg/kg for zinc and limit of quantification was from 9.2 E-4 mg/kg for pyridoxine to 4.21 mg/kg for zinc. Thereby the optimized methods demonstrated reliability and sensitivity in the detection and quantification of these micronutrients and that they are suitable for routine analysis of fortified kernels (coated and extruded) and fortified rice.

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi
Keyword(s):  
Standard Method ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Cerium Ion ◽  
Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

Recent Trends in Development of Nanomaterials Based Green Analytical Methods for Environmental Remediation

2020 ◽  
Vol 16 ◽  
Author(s):  
Sidra Amin ◽  
Amber R. Solangi ◽  
Dilawar Hassan ◽  
Nadir Hussain ◽  
Jamil Ahmed ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Environmental Remediation ◽  
Environmental Chemistry ◽  
Limit Of Detection ◽  
Environmental Pollutants ◽  
Toxic Metal ◽  
Electrochemical Analysis ◽  
Good Choice ◽  
Nano Materials ◽  
Limit Of Quantification

Background: In recent years, the occurrence and fate of environmental pollutants has been recognized as one of the emerging issues in environmental chemistry. A survey documented about a wide variety of these pollutants, which are often detected in our environment and these are major cause of shortened life spans and the global warming. These pollutants include toxic metal, pesticides, fertilizers, drugs and dyes released into soil and major water bodies. The presence of these contaminants causes major disturbance in eco-system’s balance. To tackle these issues many technological improvements are made to detect minute contaminations. The latest issue being answered by the scientists is the use of green nano materials as sensors which are economical, instant and give much better results at low concentrations and can be used for the field measurements resulting in no dangerous by-product that could lead to more environmental contamination. Nano materials are known for their wide band gap, enhanced physical and optical properties with option of tuneablity as per need, by optimizing certain parameters. They are proved to be good choice for analytical/optical sensors with high sensitivity. Objective: This review holds information about multiple methods that use green nanomaterials for the analytical assessment of environmental pollutants. UV-Vis spectrophotometry and electrochemical analysis using green and reproducible nanomaterials are the major focus of this review article. To date, there are number of spectrophotometric and electro chemical methods available that have been used for the detection of environmental pollutants such as toxic metals, pesticides and dyes. Conclusion: The use of nanomaterials can drastically change the detection limits due to having large surface area, strong catalytic properties, and tunable possibility. With the use of nano materials, lower than the marked limit of detection and limit of quantification were seen when compared with previously reported work. The used nano-materials could be washed, dried, and reused, which makes the methods more proficient, cost effective and environmentally friendly.

Calcium/Copper alginate framework doped with CuO nano-particles as a novel adsorbent for micro-extraction of benzodiazepines from human serum

2020 ◽  
Vol 16 ◽  
Author(s):  
Nadereh Rahbar ◽  
Fatemeh Ahmadi ◽  
Zahra Ramezani ◽  
Masoumeh Nourani
Keyword(s):  
Human Serum ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Nano Particles ◽  
Limit Of Quantification ◽  
Analytical Methodology ◽  
Fiber Fabrication ◽  
Relative Standard ◽  
Green Procedure

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO nanoparticles hydrogel fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear ranging between 0.1–500 µg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 µg L−1. Within-day and between-day relative standard deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

Eco-Friendly Green Liquid Chromatographic Separations of a Novel Combination of Azelastine and Fluticasone in the Presence of their Pharmaceutical Dosage form Additives

2020 ◽  
Vol 16 (3) ◽  
pp. 277-286
Author(s):  
Amal A. El-Masry ◽  
Mohammed E. A. Hammouda ◽  
Dalia R. El-Wasseef ◽  
Saadia M. El-Ashry
Keyword(s):  
Lower Limit ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Sodium Dodecyl ◽  
Uv Detection ◽  
Simultaneous Estimation ◽  
Limit Of Quantification ◽  
Chromatographic Separations ◽  
Pharmaceutical Dosage Form ◽  
Liquid Chromatographic

Background: The first highly sensitive, rapid and specific green microemulsion liquid chromatographic (MELC) method was established for the simultaneous estimation of fluticasone propionate (FLU) and azelastine HCl (AZL) in the presence of their pharmaceutical dosage form additives (phenylethyl alcohol (PEA) and benzalkonium chloride (BNZ)). Methods: The separation was performed on a C18 column using (o/w) microemulsion as a mobile phase which contains 0.2 M sodium dodecyl sulphate (SDS) as surfactant, 10% butanol as cosurfactant, 1% n-octanol as internal phase and 0.3% triethylamine (TEA) adjusted at pH 6 by 0.02 M phosphoric acid; with UV detection at 220 nm and programmed with flow rate of 1 mL/min. Results: The validation characteristics e.g. linearity, lower limit of quantification (LOQ), lower limit of detection (LOD), accuracy, precision, robustness and specificity were investigated. The proposed method showed linearity over the concentration range of (0.5-25 µg/mL) and (0.1-25 µg/mL) for FLU and AZL, respectively. Besides that, the method was adopted in a short chromatographic run with satisfactory resolution factors of (2.39, 3.78 and 6.74 between PEA/FLU, FLU/AZL and AZL/BNZ), respectively. The performed method was efficiently applied to pharmaceutical nasal spray with (mean recoveries ± SD) (99.80 ± 0.97) and (100.26 ± 0.96) for FLU and AZL, respectively. Conclusion: The suggested method was based on simultaneous determination of FLU and AZL in the presence of PEA and BNZ in pure form, laboratory synthetic mixture and its combined pharmaceutical dosage form using green MELC technique with UV detection. The proposed method appeared to be superior to the reported ones of being more sensitive and specific, as well as the separation was achieved with good performance in a relatively short analysis time (less than 7.5 min). Highly acceptable values of LOD and % RSD make this method superior to be used in quality control laboratories with of HPLC technique.

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