scholarly journals Development of a Highly Sensitive Cell-Based Assay for Detecting Botulinum Neurotoxin Type A through Neural Culture Media Optimization

2015 ◽  
Vol 21 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Won S. Hong ◽  
Hannah M. Pezzi ◽  
Andrea R. Schuster ◽  
Scott M. Berry ◽  
Kyung E. Sung ◽  
...  
Keyword(s):  
Botulinum Neurotoxin ◽  
Transforming Growth Factor ◽  
Culture Media ◽  
High Sensitivity ◽  
Transforming Growth Factor Β1 ◽  
Detection Sensitivity ◽  
Media Optimization ◽  
Sensitive Cell ◽  
Optimization Study ◽  
Highly Sensitive

Botulinum neurotoxin (BoNT) is the most lethal naturally produced neurotoxin. Due to the extreme toxicity, BoNTs are implicated in bioterrorism, while the specific mechanism of action and long-lasting effect was found to be medically applicable in treating various neurological disorders. Therefore, for both public and patient safety, a highly sensitive, physiologic, and specific assay is needed. In this paper, we show a method for achieving a highly sensitive cell-based assay for BoNT/A detection using the motor neuron–like continuous cell line NG108-15. To achieve high sensitivity, we performed a media optimization study evaluating three commercially available neural supplements in combination with retinoic acid, purmorphamine, transforming growth factor β1 (TGFβ1), and ganglioside GT1b. We found nonlinear combinatorial effects on BoNT/A detection sensitivity, achieving an EC50 of 7.4 U ± 1.5 SD (or ~7.9 pM). The achieved detection sensitivity is comparable to that of assays that used primary and stem cell–derived neurons as well as the mouse lethality assay.

scholarly journals Standardization of an LNA-based TaqMan assay qPCR analysis for Aspiculuris tetraptera DNA in mouse faeces

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Keishiro Isayama ◽  
Kenji Watanabe ◽  
Mariko Okamoto ◽  
Tomoaki Murata ◽  
Yoichi Mizukami
Keyword(s):  
Genomic Dna ◽  
High Sensitivity ◽  
Locked Nucleic Acid ◽  
Detection Sensitivity ◽  
Taqman Assay ◽  
Highly Sensitive ◽  
Aspiculuris Tetraptera ◽  
Pcr Techniques ◽  
Quantitative Pcr Assay ◽  
Direct Microscopic Observation

Abstract Background Aspiculuris tetraptera, as a parasitic pinworm, is most frequently detected in laboratory mice, and transmission is mediated by the eggs contained in the faeces of infected mice. A highly sensitive and quantitative faeces-based diagnostic tool would be useful for the early detection of A. tetraptera to inhibit the expansion of infection. In this study, we developed a quantitative assay that exhibits high sensitivity in detecting A. tetraptera in faeces using PCR techniques. Results Endpoint PCR demonstrated the detection of A. tetraptera DNA in 0.5 ng genomic DNA extracted from the faeces of infected mice. To quantitatively detect the small amount of A. tetraptera DNA, locked nucleic acid (LNA)-based primers and LNA-based TaqMan probes were used for the quantitative PCR assay (qPCR). The combination of LNA-based DNA increased detection sensitivity by more than 100-fold compared to using normal oligo DNAs. The copy number of the A. tetraptera DNA detected was positively related to the infected faeces-derived genomic DNA with a simple linearity regression in the range of 20 pg to 15 ng of the genomic DNA. To more conveniently detect infection using faeces, the LNA-based TaqMan assay was applied to the crude fraction of the faeces without DNA purification. An assay using ethanol precipitation of the faeces yielded results consistent with those of direct microscopic observation. Conclusion The LNA-TaqMan assay developed in this study quantitatively detects A. tetraptera infection in mouse faeces.

scholarly journals Highly Sensitive, Selective, Flexible and Scalable Room-Temperature NO2 Gas Sensor Based on Hollow SnO2/ZnO Nanofibers

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6475
Author(s):  
Jiahui Guo ◽  
Weiwei Li ◽  
Xuanliang Zhao ◽  
Haowen Hu ◽  
Min Wang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Positive Impact ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Pure Sno2 ◽  
Flexible Devices ◽  
Low Concentrations ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity

Semiconducting metal oxides can detect low concentrations of NO2 and other toxic gases, which have been widely investigated in the field of gas sensors. However, most studies on the gas sensing properties of these materials are carried out at high temperatures. In this work, Hollow SnO2 nanofibers were successfully synthesized by electrospinning and calcination, followed by surface modification using ZnO to improve the sensitivity of the SnO2 nanofibers sensor to NO2 gas. The gas sensing behavior of SnO2/ZnO sensors was then investigated at room temperature (~20 °C). The results showed that SnO2/ZnO nanocomposites exhibited high sensitivity and selectivity to 0.5 ppm of NO2 gas with a response value of 336%, which was much higher than that of pure SnO2 (13%). In addition to the increase in the specific surface area of SnO2/ZnO-3 compared with pure SnO2, it also had a positive impact on the detection sensitivity. This increase was attributed to the heterojunction effect and the selective NO2 physisorption sensing mechanism of SnO2/ZnO nanocomposites. In addition, patterned electrodes of silver paste were printed on different flexible substrates, such as paper, polyethylene terephthalate and polydimethylsiloxane using a facile screen-printing process. Silver electrodes were integrated with SnO2/ZnO into a flexible wearable sensor array, which could detect 0.1 ppm NO2 gas after 10,000 bending cycles. The findings of this study therefore open a general approach for the fabrication of flexible devices for gas detection applications.

scholarly journals TRANSFORMING GROWTH FACTOR-β1 EXPRESSION IN VARIOUS CONCENTRATIONS OF ADVANCED PLATELET-RICH FIBRIN MODULATING HUMAN DENTAL PULP STEM CELL DIFFERENTIATION

2020 ◽  
pp. 38-40
Author(s):  
ANGGRAINI MARGONO ◽  
DINI ASRIANTI ◽  
FRIEDA AYU PRIHADINI ◽  
INDAH JULIANTO
Keyword(s):  
Dental Pulp ◽  
Transforming Growth Factor ◽  
Culture Media ◽  
Stem Cell Differentiation ◽  
Transforming Growth Factor Β1 ◽  
Serum Starvation ◽  
Differentiation Process ◽  
Platelet Rich Fibrin ◽  
Human Dental Pulp ◽  
Tgf Β1

Objective: Modification of the speed and time of centrifugation based on the low-speed centrifugation concept for platelet-rich fibrin (PRF) has resulted in a new type of PRF known as advanced PRF (A-PRF). A-PRF can release several types of growth factors (GFs) that participate in the process of differentiation, such as transforming GF-β1 (TGF-β1). The aim of this study was to analyze TGF-β1 expression in various concentrations of A-PRF in the differentiation process of human dental pulp stem cells (hDPSCs).Methods: hDPSC cultures were obtained from those of previous research (ethical approval form has been attached). These hDPSCs were in the 2nd–3rd passage, and serum starvation was done by reducing fetal bovine serum (FBS) levels in the hDPSC culture media. A-PRF was obtained using 10 ml blood collected from the cubital vein, which was centrifuged at 1500 rpm for 14 min and then divided into four concentration groups. TGF-β1 expression in 1%, 5%, and 25% A-PRF as well as in 10% FBS (control) was analyzed by ELISA on day 7.Results: Although no significant differences were observed in TGF-β1 expression between 1%, 5%, and 25% A-PRF, and 10% FBS, it was observed that the higher the concentration of A-PRF, the greater the TGF-β1 expression.Conclusion: The expression of TGF-β1 was consistent with the increase in A-PRF concentration. The highest TGF-β1 expression was detected in 25% A-PRF among all concentrations in the differentiation process of hDPSCs.

High-sensitivity detection of gold labels by high-angle dark-field STEM imaging

1990 ◽  
Vol 48 (3) ◽  
pp. 892-893 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
High Sensitivity ◽  
Dark Field ◽  
Bright Field ◽  
Backscattered Electron Imaging ◽  
Backscattered Electrons ◽  
Average Atomic Number ◽  
Highly Sensitive ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
High Sensitivity Detection

Labelling of antibodies with small gold probes is a highly sensitive technique for detecting specific molecules in biological tissue. Larger gold probes are usually well visible in TEM or STEM Bright-Field images of unstained specimens. In stained specimens, however, the contrast of the stain is frequently the same as that of the gold labels, making it virtually impossible to identify the labels, especially when smaller gold labels are used to increase the sensitivity of the immunolabelling technique. TEM or STEM Dark-Field images fare no better (Figs. 1a and 2a), again because of the absence of a clear contrast difference between gold labels and stain.Potentially much more useful is backscattered-electron imaging, since this will show differences in average atomic number which are sufficiently large between the metallic gold and the stains normally used. However, for the thin specimens and at high accelerating voltages of the STEM, the yield of backscattered electrons is very small, resulting in a very weak signal. Consequently, the backscattered-electron signal is often too noisy for detecting small labels, even for large spot sizes.

583: Transforming Growth Factor β1 and its Receptors are Related to the Development, Recurrence and Prgression of Human Bladder Cancers

2005 ◽  
Vol 173 (4S) ◽  
pp. 159-159
Author(s):  
Wun-Jae Kim ◽  
ChangYi Quan ◽  
Pil-Du Jeoung ◽  
Eun-Jung Kim ◽  
Ji-Yeon Kim ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Human Bladder
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