Archive for the ‘Hot Articles’ Category

Shrinking Lab-on-a-Chip to Lab-in-a-Tube

Throughout a series of Lab on a Chip Focus Articles Samuel Sánchez, research group leader at Max Planck Institute for Intelligent Systems and recently elected as “innovator of the year 2014”, will be highlighting cutting-edge reports based on miniaturized devices that bridge functional materials and bio-related applications. And first up we have…Lab-in-a-Tube!

Lab-on-a-chip already scales down several components and integrates them into one device, but now scientists are working toward shrinking this further to develop entire laboratories inside an ultra-compact architecture such as a small tube. Samuel discusses the concept and advantages of the lab-in-a-tube before highlighting remarkable cell studies that have already been performed using microtubes.

Lab-in-a-tube systems can combine several functionalities such as optical or electrochemical sensing and is therefore used in various detection systems. Samuel describes the developments in this area, leading to the fabrication of a highly sensitive rolled-up optofluidic ring resonator – fully integrated into lab-on-a-chip devices of course!

Label-free detection systems using the lab-in-a-tube concept

Finally, Samuel discusses the challenges of controlling fluid flow at the micro scale and the use of self-powered on-chip micropumps. As one of Samuel’s main interests, catalytic micropumps will be discussed further in an upcoming Focus Article.

Samuel’s full article ‘Lab-in-a-tube systems as ultra-compact devices’ can be downloaded for free* on our website. We hope you enjoy reading his summary of recent advances in this new and exciting concept of chip integration.

Don’t miss Samuel’s next focus article – register for our e-alerts now!

*Access is free through a publishing personal account. It’s quick, easy and free to register.

More about Samuel Sánchez

Samuel earned his PhD in Analytical Chemistry from the Autonomous University of Barcelona in 2008. After a short period as an Assistant Professor, he worked in Japan at the National Institute for Materials Science. In 2010 he moved to the Institute for Integrative Nanoscience at the Leibniz Institute in Dresden where he was leading the “Biochemical Nanomembranes” group. He is now leading the independent research group at the Max Planck Institute for Intelligent Systems. Samuel has received several awards for his work including the Guinness World Record® for “The smallest man-made jet engine” in 2010, the IIN-IFW Research Prize 2011, the ERC-Starting Grant 2012 “Lab-in-a-tube and Nanorobotic Biosensors (LT-NRBS).” Recently, Samuel has been names as Spain’s top innovators under 35 by the Spanish edition of the journal MIT Technology Review.

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)

October’s HOT Free Articles

These HOT articles, published in October 2014 were recommended by our referees and are free* to access for 4 weeks

Optofluidic lasers with a single molecular layer of gain
Qiushu Chen, Michael Ritt, Sivaraj Sivaramakrishnan, Yuze Sun and Xudong Fan
Lab Chip, 2014,14, 4590-4595
DOI: 10.1039/C4LC00872C, Communication

A self-powered one-touch blood extraction system: a novel polymer-capped hollow microneedle integrated with a pre-vacuum actuator
Cheng Guo Li, Manita Dangol, Chang Yeol Lee, Mingyu Jang and Hyungil Jung
Lab Chip, 2015, Advance Article
DOI: 10.1039/C4LC00937A, Paper


Design of a 2D no-flow chamber to monitor hematopoietic stem cells
Théo Cambier, Thibault Honegger, Valérie Vanneaux, Jean Berthier, David Peyrade, Laurent Blanchoin, Jerome Larghero and Manuel Théry
Lab Chip, 2015,15, 77-85
DOI: 10.1039/C4LC00807C, Paper


Take a look at our Lab on a Chip 2014 HOT Articles Collection!

*Access is free until 5.01.14 through a publishing personal account. It’s quick, easy and free to register!

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)

September’s HOT Free Articles

These HOT articles, published in September 2014 were recommended by our referees and are free* to access for 4 weeks

1000-fold sample focusing on paper-based microfluidic devices
Tally Rosenfeld and Moran Bercovici
Lab Chip, 2014,14, 4465-4474
DOI: 10.1039/C4LC00734D

A reliable and programmable acoustofluidic pump powered by oscillating sharp-edge structures
Po-Hsun Huang, Nitesh Nama, Zhangming Mao, Peng Li, Joseph Rufo, Yuchao Chen, Yuliang Xie, Cheng-Hsin Wei, Lin Wang and Tony Jun Huang
Lab Chip, 2014,14, 4319-4323
DOI: 10.1039/C4LC00806E

Application of an acoustofluidic perfusion bioreactor for cartilage tissue engineering
Siwei Li, Peter Glynne-Jones, Orestis G. Andriotis, Kuan Y. Ching, Umesh S. Jonnalagadda, Richard O. C. Oreffo, Martyn Hill and Rahul S. Tare
Lab Chip, 2014,14, 4475-4485
DOI: 10.1039/C4LC00956H


Take a look at our Lab on a Chip 2014 HOT Articles Collection!

*Access is free until 28.11.14 through a publishing personal account. It’s quick, easy and free to register!

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)

Sorting by Surfing: particles separate by riding acoustic waves

Collaborators across the University of Augsburg, Harvard University, and the University of Glasgow create a fluorescence-activated cell sorter relying on acoustofluidics to guide particles to their final location.

Traditional fluorescence-activated cell and droplet sorting (FACS, FADS) machines are expensive and require considerable time for analysis as well as maintenance (i.e., rinsing and cleaning of tubing to prepare for RNase-free processing). Cheap and disposable microfluidic devices can alleviate the expense and maintenance required, but still lag in particle sorting speed because they depend on fluidic, dielectric, and magnetic actuation to direct particles after fluorescence interrogation.

Lothar Schmid, David Weitz, and Thomas Franke overcame these issues by using traveling surface acoustic waves (SAWs) to drive particles into select channels based on readout of a fluorescent signal. The group oscillated PDMS structures from below by embedded interdigitated transducers to achieve focused acoustic radiation forces which gently moved droplets and cells via acoustic streaming.

The group was able to achieve sorting independent of cell size and compressibility on the order of 3000 particles/second into multiple outlet channels. This fast separation of particles given fluorescence signal readout enables efficient sorting of populations which vary widely in shape and volume. Further, the particles did not have to be first encapsulated into drops. This simplification avoids biohazard aerosol formation, provides higher signal to noise on the fluorescent signal interrogation, and streamlines the separation process. The group demonstrated gentle sorting of melanoma cells in a single fluid based on metabolic activity and membrane integrity. It will be exciting to see how acoustic streaming can further be used to direct particles to aid rare cell separations and cell isolations from complex samples.

You can download the full article for free* until the 24th October 2014:

Sorting drops and cells with acoustics: acoustic microfluidic fluorescence-activated cell sorter
Lothar Schmid, David A. Weitz, and Thomas Franke. Lab Chip, 2014, 14, 3710-3718.
DOI: 10.1039/C4LC00588K

*Access is free through a registered RSC account – click here to register

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)

Whole-in-One: one chamber to amplify DNA from single cells

Researchers at Virginia Tech create an elegant device to perform DNA amplification starting from whole cells by taking advantage of diffusivity differences in PCR components.

Diffusion can be friend or foe in the microscale regime, depending on the application. For active mixing, relying on diffusion can lengthen reaction time and thereby decrease reaction efficiency. But for separating reaction products, low ratios of convection to diffusion (Péclet number) enable control over elements based on their diffusivity[1]. Professors Luke Achenie and Chang Lu from the chemical engineering department at Virginia Tech took advantage of this diffusion-enabled control to combine cell lysis and PCR reactions in ‘one pot’ with temporal separation of how components add to the chamber due to diffusivity differences. Separation of cell lysis and DNA amplification steps in PCR is important as many traditional chemical reagents for cell lysis inhibit polymerases used in PCR and Phusion polymerases tolerant to surfactant lysis reagents are incompatible with downstream SYBR green dyes.

The device consists of a single reaction chamber connected on both sides to two separate loading chambers. A hydration line ensures minimal evaporation during the PCR cycle in the main chamber. The loading chambers are opened in sequence to let molecules into the reaction chamber via two-layer control valves. The substantial difference in reagent diffusivity in the lysis and amplification processes allow diffusion gradients to drive molecules from new solutions contacting the reaction chamber and replace reagents from previous steps without disturbing the DNA of interest. Taq polymerase and proteins are two orders of magnitude larger in diffusivity than typical (50 kb) DNA fragments, while primers, dNTPs, and lysis buffers are three orders smaller. Relying solely on diffusion to deliver reagents to the main chamber increases the time of the reaction, but this can be addressed by elevating the temperature or increasing concentration of starting reagents in the loading chambers.

The authors showed the functionality of their device with purified human genomic DNA as well as single cells. This work opens up new capabilities to perform multi-step preparation and amplification assays for DNA in a single chamber starting directly from few cells to a single cell.

Download the full article today – for free*

Diffusion-based microfluidic PCR for “one-pot” analysis of cells

Sai Ma, Despina Nelie Loufakis, Zhenning Cao, Yiwen Chang, Luke E Achenie and Chang Lu
DOI:10.1039/C4LC00498A

References: [1] T. M. Squires and S. R. Quake, Reviews of Modern Physics, 2005, 77, 977.

*Access is free through a registered RSC account until 19th September 2014 – click here to register

About the Webwriter


Sasha is a PhD student in bioengineering working with Professor Beth Pruitt’s Microsystems lab at Stanford University. Her research focuses on evaluating relationships between cell geometry, intracellular structure, and force generation (contractility) in heart muscle cells. Outside the lab, Sasha enjoys hiking, kickboxing, and interactive science outreach.

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)

Lab-in-a-Briefcase

In a recent paper in Lab on a Chip, a group of British researchers reported a ‘lab-in-a-briefcase’ for detection and quantification of the prostate cancer biomarker PSA in human serum and whole blood. Their lab-in-a-briefcase is a small container with a set of coated plastic capillaries, a pre-loaded microwell plate with reagents and a film scanner.

lab-in-a-briefcase

The researchers stress that their system is cheap and easy to handle, which would make it very useful for performing diagnostics in low resource areas. In addition, their lab-in-a-briefcase demonstrates the potential for point-of-care tests for prostate cancer, which would allow easy screening by non-experts in a non-clinical setting.

The concept of a lab-in-a-briefcase may have more far-reaching implications, though. Most lab-on-a-chip assays and microfluidic systems are usually developed in the context of interdisciplinary research collaborations. One research department may develop a new system, while another department has the – often unstable – samples that are used to demonstrate proof-of-concept. This complexity means that projects can quickly become logistic nightmares.

Multi-site collaborations make the portability and the standardized format that are found in the lab-in-a-briefcase and related technologies very important. It doesn’t matter if the application domain of a project is physics, biochemistry or biology. Developing a portable, standardized set-up with good documentation, automated analysis and easy read-out can contribute greatly to the success of a multi-disciplinary microfluidic engineering project, because it promotes collaboration and a wider application of the technology early on.

All of this means that the lab-in-a-briefcase is not just a niche product that is only useful for cheap point-of-care diagnostics in low resource areas. It is a design concept that anyone in the realm of microfluidic engineering needs to understand. Perhaps the concept is also applicable to the project you’re currently working on?

Go check it out for yourselves – you can download this paper fro free* for a limited time only!

Ana I. Barbosa, Ana P. Castanheira, Alexander D. Edwards and Nuno M. Reis
DOI: 10.1039/C4LC00464G, Paper

*Access is free through a registered RSC account until 29th August 2014 – click here to register

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)

Life in the Fast Lane

Microscale Inertial Flow Regimes

The Reynolds number, ratio of inertial to viscous forces, is low for most microfluidic platforms and has been approximated to zero to model most microscale fluid flows as linear and time-reversible (Stoke’s flow). Yet Dino Di Carlo’s group at the University of California- Los Angeles, among others, have shown that microfluidic systems in which Reynolds’ number ranges from 1 to 100 exhibit non-negligible inertial effects. These forces lead to separation and ordering of particles within channels by stream line crossing due to effects from the channel geometries (lift forces from the channel wall and velocity profile shear gradient). Inertial lift forces are regulated by the channel dimensions and geometry, particle diameter, and flow rate.[1]

Experimentally-derived intuitions have guided researchers to use the effects of inertial lift forces to produce high throughput flow cytometers to isolate bacteria from diluted blood samples,[2] systems capable of probing the deformability of cells to evaluate metastatic potential[3, 4] and platforms combined with Dean flow in curved channels to increase mixing of fluids or spirals to improve separation of particles.[5] Yet the physical underpinnings guiding these channel designs have been limited.

In this review, Amini and colleagues tackle many of the relationships which are important to create new devices by taking advantage of the unique contribution of inertial forces at the microscale. The behavior of non-Newtonian fluids (i.e., whole blood), the role of particle shape on focusing, particle-particle interactions, and the effect of protrusions along the channel length on flow (pillars, herringbone structures) are also discussed and can open exciting new applications in medical diagnostics, chemical synthesis, manufacturing of materials, and beyond. Inertial microfluidics platforms are en route to commercialization by Johnson & Johnson to sort rare circulating tumor cells from whole blood at 10 million cells per second (CTC-iChip[6]).

Download the full review for free* for a limited time only!

Inertial microfluidic physics
Hamed Amini, Wonhee Lee and Dino Di Carlo. Lab on a Chip, 2014, 14, 2739-2761.
DOI: 10.1039/C4LC00128A

References:
[1] D. Di Carlo, Lab on a Chip, 2009, 9, 3038-3046.
[2] A. J. Mach and D. Di Carlo, Biotechnol. Bioeng., 2010, 107, 302-311.
[3] J. S. Dudani, et al, Lab on a Chip, 2013, 13, 3728-3734.
[4] S. C. Hur, et al, Lab on a Chip, 2011, 11, 912-920.
[5] J. M. Martel and M. Toner, Scientific Reports, 2013, 3.
[6] E. Ozkumur, et al, Sci. Transl. Med., 2013, 5, 179ra47.

*Access is free through a registered RSC account until 25th August 2014 – click here to register

About the WebWriter

Sasha is a PhD student in bioengineering working with Professor Beth Pruitt’s Microsystems lab at Stanford University. Her research focuses on evaluating relationships between cell geometry, intracellular structure, and force generation (contractility) in heart muscle cells. Outside the lab, Sasha enjoys hiking, kickboxing, and interactive science outreach.

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)

200th Issue of Lab on a Chip

We are delighted to announce the publication of our 200th issue of Lab on a Chip- how we have grown!

Launched in 2001, publishing 2 issues with a total of 31 articles that year, LOC is now publishing 24 issues a year. Many of the young researchers that published in the first issue have now become Professors themselves, and many have gone on to become award winners. Read the full editorial by our Editor, Harp Minhas to find out more!

This picture shows how the image of LOC has developed from the original cover to the LOC we are familiar with today.

To celebrate this achievement, we have made all of the HOT articles in the 200th issue of LOC free* to access throughout August. Click on the links below to download.

Ana I. Barbosa, Ana P. Castanheira, Alexander D. Edwards and Nuno M. Reis
Lab Chip, 2014, 14, 2918-2928
DOI: 10.1039/C4LC00464G
Yu-Chih Chen, Yu-Heng Cheng, Hong Sun Kim, Patrick N. Ingram, Jacques E. Nor and Euisik Yoon
Lab Chip, 2014, 14, 2941-2947
DOI: 10.1039/C4LC00391H

Lab on a Chip itself has had an enormous influence on the development of the field, by setting very high scientific standards, by providing a common forum and vocabulary, by highlighting significant results, and by attracting some of the best scientists. The journal, and Harp Minhas as the spirit of the journal, have provided a coherence to Lab-on-a-chip science and technology that have had enormous influence in channeling the direction of the field”

Professor George Whitesides, Chair of Editorial Board, Lab on a Chip

*Access is free through a registered RSC account until 31st August 2014 – click here to register

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)

New challenges spawn new innovations

Emerging Investigators

Guest edited by Dino di Carlo, Helene Andersson-Svah and Yanyi Huang, this issue celebrates the best and brightest amongst early career miniaturisation scientists around the world. Their editorial reflects on the past before introducing the upcoming challenges that new generations of investigators are facing. These challenges are demonstrated in the range of topics covered in this issue.

Read the full Emerging Investigator themed collection now – we hope you enjoy the articles

This issue features three HOT articles, which received particularly high scores at peer review. They are free* to access for a limited time only so click on the links below to download the full articles

Wei Liu, Yaqian Li, Siyu Feng, Jia Ning, Jingyu Wang, Maling Gou, Huijun Chen, Feng Xu and Yanan Du
Lab Chip, 2014, 14, 2614-2625
DOI: 10.1039/C4LC00081A
Lab Chip, 2014, 14, 2626-2634
DOI: 10.1039/C4LC00039K
J.-P. Frimat, M. Bronkhorst, B. de Wagenaar, J. G. Bomer, F. van der Heijden, A. van den Berg and L. I. Segerink
Lab Chip, 2014, 14, 2635-2641
DOI: 10.1039/C4LC00050A

*Access is free through a registered RSC account untill 22nd September 2014 – click here to register

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)

Free access to HOT articles

These HOT articles were recommended by our referees and are free to access for 4 weeks*

Hepatic organoids for microfluidic drug screening
Sam H. Au, M. Dean Chamberlain, Shruthi Mahesh, Michael V. Sefton and Aaron R. Wheeler  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00531G, Paper

Graphical abstract: Hepatic organoids for microfluidic drug screening
Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels
Raphaël Trouillon and Martin A. M. Gijs  
Lab Chip, 2014,14, 2929-2940
DOI: 10.1039/C4LC00493K, Paper

Graphical abstract: Delayed voltammetric with respect to amperometric electrochemical detection of concentration changes in microchannels
 
A droplet-based heterogeneous immunoassay for screening single cells secreting antigen-specific antibodies
Samin Akbari and Tohid Pirbodaghi  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00082J, Communication

Graphical abstract: A droplet-based heterogeneous immunoassay for screening single cells secreting antigen-specific antibodies
A lab-in-a-briefcase for rapid prostate specific antigen (PSA) screening from whole blood
Ana I. Barbosa, Ana P. Castanheira, Alexander D. Edwards and Nuno M. Reis  
Lab Chip, 2014,14, 2918-2928
DOI: 10.1039/C4LC00464G, Paper
Graphical abstract: A lab-in-a-briefcase for rapid prostate specific antigen (PSA) screening from whole blood

Induced charge electroosmosis micropumps using arrays of Janus micropillars
Joel S. Paustian, Andrew J. Pascall, Neil M. Wilson and Todd M. Squires  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00141A, Paper

Graphical abstract: Induced charge electroosmosis micropumps using arrays of Janus micropillars
Nanoshuttles propelled by motor proteins sequentially assemble molecular cargo in a microfluidic device
Dirk Steuerwald, Susanna M. Früh, Rudolf Griss, Robert D. Lovchik and Viola Vogel  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00385C, Paper

Graphical abstract: Nanoshuttles propelled by motor proteins sequentially assemble molecular cargo in a microfluidic device
Femtosecond laser 3D micromachining: a powerful tool for the fabrication of microfluidic, optofluidic, and electrofluidic devices based on glass
Koji Sugioka, Jian Xu, Dong Wu, Yasutaka Hanada, Zhongke Wang, Ya Cheng and Katsumi Midorikawa  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00548A, Critical Review

Graphical abstract: Femtosecond laser 3D micromachining: a powerful tool for the fabrication of microfluidic, optofluidic, and electrofluidic devices based on glass
Continuous microcarrier-based cell culture in a benchtop microfluidic bioreactor
F. Abeille, F. Mittler, P. Obeid, M. Huet, F. Kermarrec, M. E. Dolega, F. Navarro, P. Pouteau, B. Icard, X. Gidrol, V. Agache and N. Picollet-D’hahan  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00570H, Paper

Graphical abstract: Continuous microcarrier-based cell culture in a benchtop microfluidic bioreactor
Multiplexed immunoassay based on micromotors and microscale tags
D. Vilela, J. Orozco, G. Cheng, S. Sattayasamitsathit, M. Galarnyk, C. Kan, J. Wang and A. Escarpa  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00596A, Paper

Graphical abstract: Multiplexed immunoassay based on micromotors and microscale tags
Double emulsions from a capillary array injection microfluidic device
Luoran Shang, Yao Cheng, Jie Wang, Haibo Ding, Fei Rong, Yuanjin Zhao and Zhongze Gu  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00698D, Communication

Graphical abstract: Double emulsions from a capillary array injection microfluidic device
SU-8 as a material for lab-on-a-chip-based mass spectrometry
Steve Arscott  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00617H, Tutorial Review

Graphical abstract: SU-8 as a material for lab-on-a-chip-based mass spectrometry
Sorting drops and cells with acoustics: acoustic microfluidic fluorescence-activated cell sorter
Lothar Schmid, David A. Weitz and Thomas Franke  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00588K, Paper

Graphical abstract: Sorting drops and cells with acoustics: acoustic microfluidic fluorescence-activated cell sorter
Physics and technological aspects of nanofluidics
Lyderic Bocquet and Patrick Tabeling  
Lab Chip, 2014, Advance Article
DOI: 10.1039/C4LC00325J, Frontier

Graphical abstract: Physics and technological aspects of nanofluidics

 *Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

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)