demonstrating-multi-drug-resistant-mycobacterium-tuberculosis

Demonstrating a Multi-drug Resistant <em>Mycobacterium tuberculosis</em> Amplification Microarray

Simplifying microarray workflow is a necessary first step for creating MDR-TB microarray-based diagnostics that can be routinely used in lower-resource ...

Cyclin E, a regulator of the cell cycle, affects the behavior of breast-cancer cells. We investigated whether levels of cyclin E in the tumor correlated with survival among patients with breast cancer.

Cyclin E and survival in patients with breast cancer.

The objective of this study was to develop and validate a simple, field-portable, microarray system for monitoring microbial community structure and dynamics in groundwater and subsurface environments, using samples representing site status before acetate injection, during Fe-reduction, in the transition from Fe- to SO(4)(2-)-reduction, and into the SO(4)(2-)-reduction phase. Limits of detection for the array are approximately 10(2)-10(3) cell equivalents of DNA per reaction. Sample-to-answer results for the field deployment were obtained in 4 h. Retrospective analysis of 50 samples showed the expected progression of microbial signatures from Fe- to SO(4)(2-) -reducers with changes in acetate amendment and in situ field conditions. The microarray response for Geobacter was highly correlated with qPCR for the same target gene (R(2) = 0.84). Microarray results were in concordance with quantitative PCR data, aqueous chemistry, site lithology, and the expected microbial community response, indicating that the field-portable microarray is an accurate indicator of microbial presence and response to in situ remediation of a uranium-contaminated site.

Monitoring microbial community structure and dynamics during in situ U(VI) bioremediation with a field-portable microarray analysis system.

This report describes the development and pre-clinical testing of a new, random-access RNA sample preparation system (TruTip) for nasopharyngeal samples. The system is based on a monolithic, porous nucleic acid binding matrix embedded within an aerosol-resistant pipette tip and can be operated with single or multi-channel pipettors. Equivalent extraction efficiencies were obtained between automated QIAcube and manual TruTip methods at 10(6) gene copies influenza A per mL nasopharyngeal aspirate. Influenza A and B amended into nasopharyngeal swabs (in viral transport medium) were detected by real-time RT-PCR at approximately 745 and 370 gene copies per extraction, respectively. RNA extraction efficiency in nasopharyngeal swabs was also comparable to that obtained on an automated QIAcube instrument over a range of input concentrations; the correlation between threshold cycles (or nucleic acid recovery) for TruTip and QIAcube-purified RNA was R(2)>0.99. Preclinical testing of TruTip on blinded nasopharyngeal swab samples resulted in 98% detection accuracy relative to a clinically validated easyMAG extraction method. The physical properties of the TruTip binding matrix and ability to customize its shape and dimensions likewise make it amenable to automation and/or fluidic integration.

Rapid, simple influenza RNA extraction from nasopharyngeal samples.

The objectives of this study were to unify amplification, labeling, and microarray hybridization chemistries within a single, closed microfluidic chamber (an amplification microarray) and verify technology performance on a series of groundwater samples from an in situ field experiment designed to compare U(VI) mobility under conditions of various alkalinities (as HCO(3)(-)) during stimulated microbial activity accompanying acetate amendment. Analytical limits of detection were between 2 and 200 cell equivalents of purified DNA. Amplification microarray signatures were well correlated with 16S rRNA-targeted quantitative PCR results and hybridization microarray signatures. The succession of the microbial community was evident with and consistent between the two microarray platforms. Amplification microarray analysis of acetate-treated groundwater showed elevated levels of iron-reducing bacteria (Flexibacter, Geobacter, Rhodoferax, and Shewanella) relative to the average background profile, as expected. Identical molecular signatures were evident in the transect treated with acetate plus NaHCO(3), but at much lower signal intensities and with a much more rapid decline (to nondetection). Azoarcus, Thaurea, and Methylobacterium were responsive in the acetate-only transect but not in the presence of bicarbonate. Observed differences in microbial community composition or response to bicarbonate amendment likely had an effect on measured rates of U reduction, with higher rates probable in the part of the field experiment that was amended with bicarbonate. The simplification in microarray-based work flow is a significant technological advance toward entirely closed-amplicon microarray-based tests and is generally extensible to any number of environmental monitoring applications.

Profiling in situ microbial community structure with an amplification microarray.

Rapid, simple and efficient influenza RNA purification from clinical samples is essential for sensitive molecular detection of influenza infection. Automation of the TruTip extraction method can increase sample throughput while maintaining performance.

Article	Year
Cyclin E and survival in patients with breast cancer. The New England journal of medicine\| PubMed ID: 12432043	2002
Monitoring microbial community structure and dynamics during in situ U(VI) bioremediation with a field-portable microarray analysis system. Environmental science & technology\| PubMed ID: 20560650	2010
Rapid, simple influenza RNA extraction from nasopharyngeal samples. Journal of virological methods\| PubMed ID: 22425698	2012
Profiling in situ microbial community structure with an amplification microarray. Applied and environmental microbiology\| PubMed ID: 23160129	2013
Automated, simple, and efficient influenza RNA extraction from clinical respiratory swabs using TruTip and epMotion. Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology\| PubMed ID: 23880159	2013

Christopher Knickerbocker

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