Now, researchers at McMaster University have developed a rapid testing method using a simple paper strip that can detect E. coli in recreational water within minutes. The new tool can close the gap between outbreak and detection, improving public safety.
“Coliforms are always a big problem,” says the paper’s lead author John Brennan, a McMaster chemistry professor who holds the Canada Research Chair in Bioanalytical Chemistry. “The methods used to detect outbreaks are slow, and tend not to be portable, as they often need a lab-based amplification step prior to testing, causing a time lag between an outbreak and a beach closure.”
The Natural Sciences and Engineering Research Council of Canada funds Sentinel, a strategic research network that spans the country and is based at McMaster. Several dozen researchers are involved in its initiatives.
Bioactive paper is both old and new, Brennan explains. Since the late1950s, physicians have been using bioactive paper to test for glucose in urine. In the last several years, the area has expanded quickly and research has become very competitive as scientists work on new applications.
“It’s always a race,” Brennan says.
The new strips are coated with chemicals that react to the bacteria, and are printed using inkjet technology similar to that found in standard desktop printers. Within 30 minutes of sampling, the paper changes colour to indicate the presence of E. coli, with colours coded to represent different forms and concentrations of the bacteria.
In the future, the test should make it possible for consumers to check their water affordably and easily, without additional equipment, scientific knowledge or long waits.
“One of the problems right now is that there is no simple, fast and cheap way to test recreational water, and certainly nothing out there in the realm of rapid tests for drinking water,” Brennan says.
Field testing of the prototype strips is planned or under way in Canada and across the globe, in regions where untreated water poses particular health hazards. The results of these studies will help to refine the test strips and may lead to strips that are sensitive enough to tell whether water is safe enough to drink, says Brennan.
The standards for safe drinking water are hundreds of times tighter than those for safe swimming water. Typically, limits for safe swimming allow for a maximum of 100 to 500 cells in 100 mL of water, depending on jurisdiction. For water to be considered safe for drinking, there cannot be even one cell in 100 mL – a little less than half a cup of water.
The next stage of pre-commercial development of the test strips is already funded by NSERC through a Phase I Idea to Innovation grant. Commercialization of a final product could take as little as two to three years.LINKS:
Wade Hemsworth | Newswise Science News
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The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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