Rapid Detection of Salmonellae by Means of a New Impedance-Splitting Method

1994 ◽  
Vol 57 (5) ◽  
pp. 369-376 ◽  
Author(s):  
P. PLESS ◽  
K. FUTSCHIK ◽  
E. SCHOPF
Keyword(s):  
Magnesium Chloride ◽  
Rapid Detection ◽  
Salmonella Enteritidis ◽  
Culture Media ◽  
Splitting Method ◽  
Chloride Concentration ◽  
High Sensitivity ◽  
Food Samples ◽  
Cultural Analysis ◽  
Measuring System

An Impedance-Splitting method is proposed for the rapid detection of salmonellae in foods. The measuring System, BacTrac™ 4100, permits the registration of changes, caused by bacterial metabolism, not only of the impedance of the culture medium but also of changes in the ionic layers at the measuring electrodes, which has advantages in case of high salt concentrations. These changes are expressed as percentage decreases of the initial values, M-value and E-value, respectively. Food samples were pre-enriched 14 to 16 h at 37°C in peptone water by addition of mannitol, which facilitated the detection of salmonellae on selective culture media. Following this, 0.1 mi of the preenrichment culture was transferred to 9.9 ml of Impedance-Splitting Salmonellae (ISS) medium which consisted of magnesium chloride (hydrated), malachite green oxalate, novobiocin, phosphate buffer, mannitol, peptone and yeast extract. Despite the high magnesium chloride concentration in this medium, salmonellae produced changes of the E-value up to 100%, while the changes in M-values were limited to a few percent. The impedance changes were automatically recorded during incubation in the measuring system for up to 22 h at 40°C, and the time required to exceed a threshold value of 15% (E reaction time) was evaluated. Comparative testing of the ISS method with standard cultural analysis of 250 unknown food samples showed high sensitivity and selectivity in detecting salmonellae. From all of the 122 Salmonella-positive samples, the largest number (119) was obtained by the ISS method, as compared to that obtained by conventional testing with the selenite-cystine (106), Rappaport Vassiliadis soya (95), Rappaport Vassiliadis (92) and tetrathionate brilliant green medium (64). Six samples were false positive by Enterobacter cloaceae. One strain each of Salmonella enteritidis PT8 and Salmonella panama were not recorded. The ISS method is very suitable as a screening test, all the more since a negative investigation result will be obtained within 38 h. In view of the practicability, this method is superior to the enzyme-immunological and molecular-biological procedures.

scholarly journals A highly sensitive and selective fluorescent probe for quantitative detection of Al3+ in food, water, and living cells

RSC Advances ◽  
2019 ◽  
Vol 9 (18) ◽  
pp. 10414-10419 ◽  
Author(s):  
Qian Jiang ◽  
Mingxin Li ◽  
Jie Song ◽  
Yiqin Yang ◽  
Xu Xu ◽  
...  
Keyword(s):  
Rapid Detection ◽  
High Sensitivity ◽  
Living Cells ◽  
Food Samples ◽  
Quantitative Detection ◽  
Lower Detection Limit ◽  
Highly Sensitive ◽  
Lower Detection ◽  
Wide Ph Range ◽  
Ph Range

Probe 2a exhibiting high sensitivity, good selectivity, wide pH range, lower detection limit, and rapid detection for Al3+, probe 2a was applied for the successful detection of Al3+ in water samples, food samples and HeLa cells.

A new photometric method for oxygen consumption measurements in cell suspensions

1986 ◽  
Vol 61 (2) ◽  
pp. 449-455 ◽  
Author(s):  
W. Mueller-Klieser ◽  
R. Zander ◽  
P. Vaupel
Keyword(s):  
Volume Fraction ◽  
High Sensitivity ◽  
Cell Suspensions ◽  
Measuring System ◽  
Photometric Method ◽  
O2 Consumption ◽  
Physical Density ◽  
O2 Concentration ◽  
Consumption Rates ◽  
Time Required

A new technique is described for measuring O2 consumption rates and O2 concentrations in suspensions of respiring cells. Aliquots of a cell suspension kept in a special thermostated precision syringe are injected into the measuring system in defined time intervals. The O2 content of these samples is determined photometrically, as reported previously. The O2 consumption per cellular wet weight and/or per single cell can be calculated from the cell volume fraction, the physical density, the cell concentration in the suspension, and the time-dependent decline of the O2 concentration in the precision syringe. The minimum detectable amount of O2 is 0.1 microliter O2, which corresponds to 0.001 (vol/vol) of O2 if a 100-microliters sample of suspended cells is analyzed. Reproducibility of the O2 consumption measurement is 9% of the measured value. The advantages offered by this method are the straightforward calibration in absolute terms, the short time required for one analysis (2–6 min), a high sensitivity, the simultaneous determination of overall O2 concentration and O2 consumption rates in cell suspensions, and the great variability in the application.

Gold Immunochromatography Assay - A Newly Rapid Detection Technique for Aquatic Products

2013 ◽  
Vol 690-693 ◽  
pp. 1449-1454
Author(s):  
Yuan Wang ◽  
Hui Juan Yu ◽  
Bei Lei Qian ◽  
You Qiong Cai ◽  
Dong Mei Huang ◽  
...  
Keyword(s):  
Rapid Detection ◽  
High Sensitivity ◽  
Detection Technique ◽  
Detection Methods ◽  
Future Perspectives ◽  
Auxiliary Equipment ◽  
Basic Principles ◽  
Aquatic Products ◽  
Immunological Detection

Gold immunochromatography assay (GICA) technique has the following characteristics: rapid and simple, high sensitivity, good specificity, no auxiliary equipment, ease of interpreting results, and satisfactory stability. The technique has become one of the most rapid and sensitive immunological detection methods, which is widely used in medical, biological and other fields. The article focuses on the basic principles and technical characteristics of GICA, and briefly describes the applications and future perspectives in the rapid detection of aquatic products.

New Perspectives for SARS-CoV-2 Rapid Detection

Coronaviruses ◽  
2021 ◽  
Vol 02 ◽  
Author(s):  
Latifa Khattabi ◽  
Mustapha Mounir Bouhenna ◽  
Feriel Sellam
Keyword(s):  
Rapid Detection ◽  
High Sensitivity ◽  
The Other ◽  
Host Cells ◽  
Rt Pcr ◽  
Human Immune System ◽  
Virus Attachment ◽  
Testing Procedures ◽  
Diagnostic Kits ◽  
Human Immune

: The present paper elucidates the conceivable application of two key molecules in SARS-CoV-2 detection of suspected infected persons. These molecules were selected from the basis of ACE-2 and S protein strong interaction that allows virus attachment to its host cells, on the other hand specific immunocompetant effectors generated by human immune system during the infection. Several testing procedures are already used to diagnose SARS-CoV-2 infection, particularly RT-PCR technique. ELISA and LFIA are possible assays for the employment of shACE-2/ hAc-anti-S (the molecules of interest) as the main agents of the test and confer a dual principal functions (capture and detection). The future diagnostic kits involving shACE-2 and hAc-anti-S will have the particularity of high sensitivity and rapid detection in addition to its advantage of relatively easy conception. It could be largely considered as a technical advanced kits in regards to the current SARS-CoV-2 diagnostic immunoassays.

Rapid detection and enumeration of total bacteria in drinking water and tea beverages using a laboratory-built high-sensitivity flow cytometer

2015 ◽  
Vol 7 (7) ◽  
pp. 3072-3079 ◽  
Author(s):  
Muxin Yu ◽  
Lina Wu ◽  
Tianxun Huang ◽  
Shuo Wang ◽  
Xiaomei Yan
Keyword(s):  
Drinking Water ◽  
Rapid Detection ◽  
High Sensitivity ◽  
Flow Cytometer ◽  
Total Bacteria

This paper describes a method for the rapid detection and enumeration of total bacteria in drinking water and tea beverages.

scholarly journals Fabrication of a Food Nano-Platform Sensor for Determination of Vanillin in Food Samples

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Precipitation Method ◽  
Single Wall Carbon Nanotubes ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Paste Electrode

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

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