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

Sakamoto, Chieko; Yamaguchi, Naohito; Nasu, Masao

doi:10.1128/aem.71.2.1117-1121.2005

Cited by 64 publications

(44 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14) The bacterial numbers of E. coli O157:H7 determined by this technique were similar to those obtained by direct microscopic count (within 4 × 10 5 to 5 × 10 6 cells/ml, r 2 = 0.95). In this study, we also tested the measurement range for the analysis of bacterial cells using this on-chip flow cytometry, and found a similar measurement range (lower detection limit: 10 2 CFU/ml).…”

Section: Discussionsupporting

confidence: 62%

“…13) On-chip flow cytometry has also been applied for the enumeration of freshwater bacteria. 14) Here we report the application of commercially available on-chip flow cytometry for FISH analysis to identify L. monocytogenes in milk. Oligonucleotide Probes --Four oligonucleotide probes were used: the universal bacterial probe EUB338 (5 -GCTGCCTCCCGTAGGAGT-3 ); 15) L. monocytogenes probe RL-2 (5 -ATAGTTTTAT-GGGATTAGC-3 ); 16) E. coli probe ES445 (5 -CTT-TACTCCCTTCCTCCCC-3 ); 17) and the nonsense probe complementary to EUB338 ("non-EUB338"; 5 -ACTCCTACGGGAGGCAGC-3 ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rapid On-chip flow Cytometric Detection of Listeria monocytogenes in Milk

Ikeda

Yamaguchi

Nasu

2009

JOURNAL OF HEALTH SCIENCE

Self Cite

View full text Add to dashboard Cite

Section: Discussionsupporting

confidence: 62%

Section: Introductionmentioning

confidence: 99%

Rapid On-chip flow Cytometric Detection of Listeria monocytogenes in Milk

Ikeda

Yamaguchi

Nasu

2009

JOURNAL OF HEALTH SCIENCE

Self Cite

View full text Add to dashboard Cite

“…Although this is a uniquely designed EQA program that appears so far suitable for Xpert MTB/RIF verification using different strains from different culture methods, the individual components are not unfamiliar to the field: filter paper has been used for the transportation and molecular testing of M. tuberculosis DNA (7,14), and flow cytometry has been used for the analysis of M. tuberculosis (2,10,16,18,(20)(21)(22)(23). Flow cytometry has the advantage of rapidly and accurately identifying inactivated single whole bacterial cells, which circumvents conventional, time-consuming CFU enumeration methodologies.…”

mentioning

confidence: 99%

Dried Culture Spots for Xpert MTB/RIF External Quality Assessment: Results of a Phase 1 Pilot Study in South Africa

et al. 2011

View full text Add to dashboard Cite

Implementation of Xpert MTB/RIF requires quality assessment. A pilot program using dried culture spots (DCSs) of inactivated Mycobacterium tuberculosis is described. Of 274 DCS results received, 2.19% generated errors; the remainder yielded 100% correct Mycobacterium tuberculosis detection. The probe A cycle threshold (C T ) variability of three DCS batches was <3.47. The study of longer-term DCS stability is ongoing.The Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA) (1, 3-5, 9, 12, 13, 15, 19, 25) for the diagnosis of Mycobacterium tuberculosis has recently been endorsed by the WHO (28), and recommendations for data collection to quantify the impact of this GeneXpert (GX) technology are provided (26). Guidance, however, with respect to appropriate external quality assessment (EQA) programs is lacking (17). Current international tuberculosis (TB) EQA programs focus on microscopy, culture, and susceptibility testing laboratories (24) and highlight the difficulties in expansion due to labor-intensive preparatory work and the high cost and regulations associated with shipping drug-resistant isolates (27).Criteria for a verification ("fit for purpose") and EQA program suited to the characteristics of the Xpert MTB/RIF assay (3, 8) will require the following elements. (i) The testing material must contain whole M. tuberculosis (8).(ii) Transportation of EQA material needs to be safe. (iii) The testing procedure needs to be safe and compatible with the Xpert MTB/ RIF current testing protocol. (iv) Health care workers who do not have laboratory skills must be able to perform the testing in nonlaboratory settings. (v) Finally, the programs will need to be cost-effective and sustainable. Such a program using whole inactivated M. tuberculosis spotted onto filter paper was developed and piloted in South Africa as part of the National Health Laboratory Service (NHLS) GX rollout. H37Ra]) and well-characterized local clinical strain MYCTU 15, and (iii) the ATCC 25618 (H37Rv) laboratory strain grown for single-cell-organism suspensions (11). The MGIT cultures S-MYCTU-02-P2 and MYCTU 15 and clinical isolates were pooled in their respective batches (with strains kept separate and not mixed), centrifuged (3,000 ϫ g for 15 min at 4°C) to pellet cells, and resuspended in 40 ml phosphate-buffered saline (PBS) followed by addition of 80 ml (2:1 ratio of buffer to culture) of the Xpert sample reagent (SR) buffer. For the H37Rv strain, 200 ml of culture was harvested (by centrifugation at 3,500 ϫ g) at room temperature for 10 min, and cells were resuspended in PBS to 40 ml followed by addition of 80 ml SR buffer (2:1 ratio of buffer to cells). Both MGIT-grown and H37Rv strain cultures were inactivated in SR buffer for 2 h at room temperature, with intermittent mixing. The inactivated material was washed twice with sterile PBS and resuspended in final volumes of 10 ml (S-MYCTU-02-P2 and MYCTU 15) and 40 ml (H37Rv) PBS. For confirmation of inactivation, washed cultures (0.5 ml) were reinoculated into new MGIT tubes in Bactec cabinets fo...

show abstract

“…26,27 . Researchers have also utilized microfluidic flow cytometers for the quantification of bacterial samples from different sources 28 . Compared to conventional single-cell techniques such as fluorescent activated cell sorting (FACS) and micromanipulation on agar, microfluidics offers a unique opportunity for studying and monitoring single cells in real time.…”

Section: Microbiology and Cell Biologymentioning

confidence: 99%

Microfluidics:A Boon for Biological Research

Mahesh

Vaidya²

2017

Current Science

View full text Add to dashboard Cite

Microfluidics is an emerging new interdisciplinary field that deals with the manipulation of fluids at the microscale and nanoscale. Having its origins in other areas of science and technology, microfluidics is slowly beginning to make radical changes in various fields of biological sciences. The exclusivity of fluid behaviour at the microscale offers a large number of advantages in biological research such as miniaturization of assays, faster sample processing and rapid detection. This article provides a concise overview of the applications of microfluidics technology in some of the major disciplines of biological research. Furthermore, it also mentions the hurdles that microfluidics is facing and the solutions that are envisaged for the future to make it a widely available, reliable and costeffective technology.

show abstract

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

Cited by 64 publications

References 29 publications

Rapid On-chip flow Cytometric Detection of Listeria monocytogenes in Milk

Rapid On-chip flow Cytometric Detection of Listeria monocytogenes in Milk

Dried Culture Spots for Xpert MTB/RIF External Quality Assessment: Results of a Phase 1 Pilot Study in South Africa

Microfluidics:A Boon for Biological Research

Contact Info

Product

Resources

About