scholarly journals Rapid and Simple Quantification of Bacterial Cells by Using a Microfluidic Device

2005 ◽  
Vol 71 (2) ◽  
pp. 1117-1121 ◽  
Author(s):  
Chieko Sakamoto ◽  
Nobuyasu Yamaguchi ◽  
Masao Nasu

ABSTRACT This study investigated a microfluidic chip-based system (on-chip flow cytometry) for quantification of bacteria both in culture and in environmental samples. Bacterial numbers determined by this technique were similar to those obtained by direct microscopic count. The time required for this on-chip flow cytometry was only 30 min per 6 samples.

2019 ◽  
Vol 4 (2) ◽  
pp. 152-163 ◽  
Author(s):  
Zenib Aljadi ◽  
Frida Kalm ◽  
Harisha Ramachandraiah ◽  
Anna Nopp ◽  
Joachim Lundahl ◽  
...  

Abstract Background The flow cytometry-based basophil activation test (BAT) is used for the diagnosis of allergic response. However, flow cytometry is time-consuming, requiring skilled personnel and cumbersome processing, which has limited its use in the clinic. Here, we introduce a novel microfluidic-based immunoaffinity BAT (miBAT) method. Methods The microfluidic device, coated with anti-CD203c, was designed to capture basophils directly from whole blood. The captured basophils are activated by anti-FcεRI antibody followed by optical detection of CD63 expression (degranulation marker). The device was first characterized using a basophil cell line followed by whole blood experiments. We evaluated the device with ex vivo stimulation of basophils in whole blood from healthy controls and patients with allergies and compared it with flow cytometry. Results The microfluidic device was capable of capturing basophils directly from whole blood followed by in vitro activation and quantification of CD63 expression. CD63 expression was significantly higher (P = 0.0002) in on-chip activated basophils compared with nonactivated cells. The difference in CD63 expression on anti-FcεRI-activated captured basophils in microfluidic chip was significantly higher (P = 0.03) in patients with allergies compared with healthy controls, and the results were comparable with flow cytometry analysis (P = 0.04). Furthermore, there was no significant difference of CD63% expression in anti-FcεRI-activated captured basophils in microfluidic chip compared with flow cytometry. Conclusions We report on the miBAT. This device is capable of isolating basophils directly from whole blood for on-chip activation and detection. The new miBAT method awaits validation in larger patient populations to assess performance in diagnosis and monitoring of patients with allergies at the point of care.


2012 ◽  
pp. 1913-1923 ◽  
Author(s):  
Shady Gawad ◽  
Ana Valero ◽  
Thomas Braschler ◽  
David Holmes ◽  
Philippe Renaud ◽  
...  
Keyword(s):  

2020 ◽  
Vol 15 (5) ◽  
pp. 296-301
Author(s):  
Salini Krishna ◽  
Fadi Alnaimat ◽  
Ali Hilal‐Alnaqbi ◽  
Saud Khashan ◽  
Bobby Mathew
Keyword(s):  

2018 ◽  
Vol 4 (7) ◽  
pp. 956-963 ◽  
Author(s):  
Yanzhe Zhu ◽  
Xiao Huang ◽  
Xing Xie ◽  
Janina Bahnemann ◽  
Xingyu Lin ◽  
...  

A microfluidic chip for differentiating liveversusdead cells was designed and tested experimentally with lab and environmental samples.


2016 ◽  
Vol 229 ◽  
pp. 7-13 ◽  
Author(s):  
Casper Kunstmann-Olsen ◽  
Martin M. Hanczyc ◽  
James Hoyland ◽  
Steen Rasmussen ◽  
Horst-Günter Rubahn

2010 ◽  
Vol 77 (4) ◽  
pp. 1536-1539 ◽  
Author(s):  
Nobuyasu Yamaguchi ◽  
Masashi Torii ◽  
Yuko Uebayashi ◽  
Masao Nasu

ABSTRACTA microfluidic device-based system for the rapid and semiautomated counting of bacteria in freshwater was fabricated and examined. Bacteria in groundwater and in potable water, as well as starvedEscherichia coliO157:H7 spiked in pond water, were able to be on-chip stained and enumerated within 1 h using this system.


2019 ◽  
Vol 8 (2) ◽  
pp. 558-566

Flow cytometry (FCM) was first developed for medical and clinical applications such as hematology and oncology. Although these areas still account for the vast majority of publications on this technique, during the past few years it has been also introduced in other areas, such as optimization and monitoring of biotechnological and environmental processes, pharmacology, toxicology, bacteriology and virology. In the food and drinks industries, the time required for conventional microbiology tests can lead to substantial delays in product release to the market. FCM has been used in conjunction with viability markers for rapid counting of yeast, molds and bacterial cells, including foodborne pathogens and microbial contaminants, in food products as well as for monitoring and improving the final products quality. FCM is an excellent tool, still unexplored in clinical microbiology, allowing for detection of cellular and non-cellular components in different clinical specimens, the study of antimicrobial activity, allowing for rapid and direct antimicrobial susceptibility testing and for the investigation of resistance mechanisms. Recent FCM developments important for addressing questions in environmental microbiology include the study of microbial physiology under environmentally relevant conditions, the development of new methods to identify active microbial populations and to isolate previously uncultured microorganisms and of high-throughput autofluorescence bioreporter assays. Moreover, the technological advancements will make possible the miniaturisation and automation of FCM devices, allowing to revolutionize their applications in the near future. The purpose of this minireview is to update the current applications of FCM in different fields of applied microbiology, and to highlight the main advantages and pitfalls for each of them.


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