Archive for February, 2011

Crime scene DNA testing on the move

A microfluidic chip that can come up with a DNA profile in less than three hours has been designed by US scientists for use at crime scenes.

With current techniques, forensic scientists have to wait up to eight hours to get results. Using microchips to speed up the process has been investigated but integrating all of the profiling steps in one device has remained elusive until now. Richard Mathies from the University of California, Berkeley, and colleagues, in collaboration with the US Department of Justice, have produced a portable method to test DNA at a crime scene that integrates all of the steps in one device.

Andy Hopwood, an expert in DNA analysis techniques from the UK’s Forensic Science Service, believes that the work is ‘without a doubt a very exciting and significant development toward the total integration of the DNA-based human identification process onto a single microchip’.

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

Integrated DNA purification, PCR, sample cleanup, and capillary electrophoresis microchip for forensic human identification
Peng Liu, Xiujun Li, Susan A. Greenspoon, James R. Scherer and Richard A. Mathies
Lab Chip, 2011, 11, 1041
DOI: 10.1039/c0lc00533a

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

HOT: SERS microfluidic device for fast and reliable bacteria identification

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

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Chips make short work of RNA synthesis

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

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

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

LOC Issue 4 now available online!

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

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)