Lab on a Chip Blog

HOT: SERS microfluidic device for fast and reliable bacteria identification

03 Feb 2011

Want your bacteria identified – wait one second!

A team from the Friedrich-Schiller University of Jena have designed a SERS microfluidic system for swiftly analysing large sample sets of bacteria. Jürgen Popp and co-workers have combined the benefits that a lab-on-a-chip provides – a well defined detection area – with the sensitivities of SERS for fast, reproducible spectra every time. Their novel sample technique, which involves sonicating the bacteria to break down the cell walls, avoids previous problems with spectral fluctuations and sample inhomogeneity.

Read how they did it here – the article is free to access until the end of February!

Towards a fast, high specific and reliable discrimination of bacteria on strain level by means of SERS in a microfluidic device
Angela Walter, Anne März, Wilm Schumacher, Petra Rösch and Jürgen Popp
Lab Chip, 2011, Advance Article
DOI: 10.1039/C0LC00536C, Paper

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Chips make short work of RNA synthesis

03 Feb 2011

By Rachel Blakeburn.

Chinese scientists have developed a much easier way to make the short strands of RNA that are an essential tool in understanding what genes do.

Short interfering ribonucleic acids (siRNAs) were first discovered in 1999, and found to interfere with the expression of specific genes, giving them a key role in controlling the molecular machinery in living organisms. Though initially identified in plants, they were later found in animals too, and this spurred an interest in using them as tools to investigate what specific genes do in the body.

One type of siRNAs, endoribonuclease-prepared siRNAs (esiRNAs), has recently attracted attention because of their greater specificity and their cost effectiveness. Jianzhong Xi and colleagues at Peking University have now demonstrated a lab on a chip method that makes large scale manufacture of esiRNAs much easier.

The chip consists of 96 pins. Each pin has a polymer bead at its end in which a number of DNA probes are immobilised, allowing hundreds of esiRNA products to be manipulated at the same time.

Read Catherine Bacon’s Chemistry World article online here or go straight to the HOT Lab on a Chip paper:

A polyacrylamide microbead-integrated chip for the large-scale manufacture of ready-to-use esiRNA
Huang Huang, Qing Chang, Changhong Sun, Shenyi Yin, Juan Li and Jianzhong Jeff Xi
Lab Chip, 2011, 11, Advance Article
DOI: 10.1039/C0LC00564A

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LOC Issue 4 now available online!

02 Feb 2011

By Francesca Burgoyne.

LOC issue 4 is now available to view online here.

The cover articles by Volkert van Steijn (Delft University of Technology) and Shuichi Takayama (University of Michigan) on monodisperse hydrogel microspheres and cell death & detachment in a microfluidic alveolar model, respectively, are both free to access for 6 weeks.

The issue also features a tutorial review by Mazher-Iqbal Mohammed and Marc Desmulliez (Heriot-Watt University) on miniature biosensor technologies for cardiac biomarkers and a host of HOT papers.

Monodisperse hydrogel microspheres by forced droplet formation in aqueous two-phase systems
Iwona Ziemecka, Volkert van Steijn, Ger J. M. Koper, Michel Rosso, Aurelie M. Brizard, Jan H. van Esch and Michiel T. Kreutzer
Lab Chip, 2011, 11, 620-624
DOI: 10.1039/C0LC00375A

Combination of fluid and solid mechanical stresses contribute to cell death and detachment in a microfluidic alveolar model

Nicholas J. Douville, Parsa Zamankhan, Yi-Chung Tung, Ran Li, Benjamin L. Vaughan, Cheng-Feng Tai, Joshua White, Paul J. Christensen, James B. Grotberg and Shuichi Takayama
Lab Chip, 2011, 11, 609-619
DOI: 10.1039/C0LC00251H

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Microfluidic pinball

10 Jan 2011

By Jackie Cockrill, Publishing Assistant.

A device to deposit polymer layers on oil droplets has been made by researchers from Singapore, who say that their design is faster and

Oil droplets are guided through three liquid streams - two polymers and a washing station - by micropillars arranged in a zigzag fashion

more efficient than conventional deposition techniques and it achieves the highest number of polymer layers reported so far using microfluidics. The device could be used to encapsulate drugs for delivery or be used to create capsules for biosensing.

Dieter Trau from the National University of Singapore and colleagues have used a method that they call ‘microfluidic pinball’ to guide oil droplets through channels created by rows of micropillars, like a pinball machine. The rows are orientated in a zigzag fashion across three liquid streams – two polymers and a washing station. The angles created by the rows, as well as the flow rates in the streams, determine how long droplets stay in each channel.

The droplets are guided along the rows to travel repeatedly through the three streams. The team found that six polyelectrolyte layers could be deposited on a droplet in under three minutes – they were able to see the layers with fluorescence spectroscopy. Atomic force microscopy revealed the thickness of each layer to be approximately 2.8nm.

Read Jennifer Newton’s Chemistry World article online here or go straight to the HOT Lab on a Chip paper:

A microfluidic pinball for on-chip generation of Layer-by-Layer polyelectrolyte microcapsules

Chaitanya Kantak, Sebastian Beyer, Levent Yobas, Tushar Bansal and Dieter Trau,
Lab Chip, 2011
DOI: 10.1039/c0lc00381f

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Ferrofluids help you see better

23 Dec 2010

By Jackie Cockrill, Publishing Assistant.

US researchers have used ferrofluids as liquid pistons that could be used to make adjustable liquid lenses with nearly perfect spherical interfaces for applications such as an optometrist’s phoropter. A phoropter measures the way light is focused in the eye and is used to determine prescriptions for glasses and contact lenses.

Ferrofluids are colloidal solutions of ferromagnetic nanoparticles suspended in a dispersing liquid. Ferrofluid droplets can be manipulated by a magnetic field, so they could be used in systems that need precise control, such as optics, drug delivery, and electronic devices.

Amir Hirsa and colleagues from Rensselaer Polytechnic Institute in Troy, New York, have made such a device by filling three of four holes in a substrate with ferrofluid; the ferrofluid’s surface tension allows droplets to protrude from either side of the substrate. They filled the fourth hole with 1-methylnaphthalene, a compound used as a liquid lens. They sealed the system and filled it with water, producing two chambers, with the substrate as the separator and the ferrofluid and 1-methylnaphthalene being the only connections between them.

As a magnetic field was applied to the device, the ferrofluid moved further into one chamber, pushing the 1-methylnaphthalene liquid lens and changing its curvature

Read the full story here

Link to journal article
Electromagnetic liquid pistons for capillarity-based pumping
Bernard A. Malouin Jr, Michael J. Vogel, Joseph D. Olles, Lili Cheng and Amir H. Hirsa,
Lab Chip, 2011, DOI: 10.1039/c0lc00397b

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Stephen Quake wins Pioneers of Miniaturisation Lectureship

15 Dec 2010

By Michael Smith.

Congratulations to Professor Steve Quake from Stanford University who is the 2010 winner of the Lab on a Chip/Corning Inc. Pioneers of Miniaturisation Lectureship.

The prize was presented during the uTAS meeting held in Groningen, Netherlands this year. It is awarded annually to an early to mid-career scientist for extraordinary or outstanding contributions to the understanding or development of miniaturised systems and includes a prize of $5000 ($2000 of which may be used to attend the µTAS Symposium).

Professor Quake’s research interests include biological automation tools, microfluidic large scale integration (demonstrating the first devices with thousands of integrated mechanical valves), single molecule DNA sequencing and much more.

Take a look at the webpage for more details about the prize jointly sponsored by Corning Inc.

View the photos and further information from about the 2010 uTAS meeting in Gronongen.

Read Steve Quake’s recent article in Lab on a Chip with reference to ‘biotic games’

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Lung implant is a breath of fresh air

14 Dec 2010

By Jackie Cockrill, Publishing Assistant.

Artificial lung technology could reduce the death rate for patients awaiting a lung transplant, say US scientists.

Advanced lung disease is characterised by an inability to remove carbon dioxide from the blood and reduced oxygen uptake efficiency. A shortage of donors can mean long delays and high mortality rates for those awaiting a transplant. The only technology available to aid sufferers during this time is based in intensive care units, hindering quality of life.

Now, Joseph Vacanti and coworkers at Massachusetts General Hospital, Boston, have developed a device that achieves the CO2/O2 gas exchange that, when implanted in the body, could allow patients more freedom when awaiting a transplant. Their design is a microfluidic branched vascular network through which blood flows, separated from a gas-filled chamber by a silicone membrane less than 10um thick. The network is formed by casting polydimethylsiloxane, a biocompatible polymer, on a micro machined mould.

A device that achieves carbon dioxide/oxygen gas exchange could allow patients more freedom when awaiting a lung transplant

Read the full story here

Link to journal article
Lung assist device technology with physiologic blood flow developed on a tissue engineered scaffold platform
David M. Hoganson, Howard I. Pryor II, Erik K. Bassett, Ira D. Spool and Joseph P. Vacanti, Lab Chip, 2011
DOI: 10.1039/c0lc00158a

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Shrink Nanotechnologies/Corning collaboration

08 Dec 2010

By Michael Smith.

A recent agreement between Shrink Nanotechnologies and Corning now means Shrink will be able to offer Corning’s complete SmartBuild Plug-n-Play Modular Microfluidic System to researchers. This system enables the building of larger lab-on-a-chip devices by connecting multiple components together and was developed by Corning’s Po Ki Yuen and colleagues.

Shrink Nanotechnologies was founded by Michelle Khine. With fellow colleagues at the University of California she devized the ‘shrinky-dink’ technology for production of custom microfluidic devices in minutes.

Read a fuller account of the Shrink/Corning collaboration and take a look at the Lab on a Chip articles featuring the ‘Shrinky-dink’ technology and the plug-n-play modular microfluidics system.

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Lab on a Chip Blog

HOT: SERS microfluidic device for fast and reliable bacteria identification

Chips make short work of RNA synthesis

LOC Issue 4 now available online!

Top ten most accessed articles in December

Top ten most accessed articles in November

Microfluidic pinball

Ferrofluids help you see better

Stephen Quake wins Pioneers of Miniaturisation Lectureship

Lung implant is a breath of fresh air

Shrink Nanotechnologies/Corning collaboration

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