New thematic collection open for submissions – Miniaturized Sensors and Diagnostics

We are delighted to announce a new thematic collection in Lab on a Chip, focusing on miniaturized sensors and diagnostics, with Professors Yoon-Kyoung Cho and Xingyu Jiang as Thought Leaders.

Our journal is the home for cutting-edge reports about innovations in the “lab on a chip,” which by nature involves developments in microfluidics, sensors, optics, electronics, imaging, materials, mechanical components, and more. In this thematic collection, we focus on the critical importance of the sensor to the lab on a chip, whether the sensor relies on optical, chemical, electrical, or mechanical forces (or many others). This collection also focuses on how lab on a chip/sensor systems are being used to form the next-generation of miniaturized diagnostics, whether they are implantable, wearable, portable, or simply used in the lab.

This on-going collection is collated by Thought Leaders (and Lab on a Chip Editorial Board members) Yoon-Kyoung Cho, Xingyu Jiang and the Lab on a Chip Editorial Office. Are you interested in submitting? We welcome submissions of original research articles and reviews, which (after peer review) will be published and added to the online collection. Papers in this collection will receive extensive promotion throughout the submission period and also will be disseminated widely as a ‘flagship’ collection for the journal. If you are interested in submitting to the series, please get in touch with the Lab on a Chip Editorial Office at loc-rsc@rsc.org

This collection open for submissions now, with a deadline of February 1st 2022

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 on a Chip & MicroTAS 2021: Our prize winners!

The hybrid µTAS 2021 meeting was held from 10-14th October, chaired by Amy Herr & Joel Voldman. We’d like to thank all those who entered the awards this year, and to the judging panels who helped us select the winners. All three prizes received excellent submissions and we’re delighted to announce the winners below.


Lab on a Chip/Dolomite Pioneers of Miniaturization Lectureship

Professor Keisuke Goda (University of Tokyo, Japan), has been awarded the 16th Pioneers of Miniaturization Lectureship, sponsored by Dolomite and Lab on a Chip. The Pioneers of Miniaturization Lectureship rewards early to mid-career scientists who have made extraordinary or outstanding contributions to the understanding or development of miniaturised systems.
Like previous years, Professor Goda will receive a monetary award, certificate and plaque, and gave a stunning talk during the µTAS 2021 conference: “a love story of imaging and microfluidics”.


Art in Science Competition
In collaboration with Greg Cooksey from the National Institute of Standards & Technology (NIST), we were pleased to present the Art in Science award:

“Living Impression Sunrise” by Yang Du (Fudan University, China)

An fluorescent image of tumor pre-metastatic perivascular niche. 3D microvessels networks formed by self-assembly of Human Umbilical Vein Endothelial Cells interacted with tumor organoids in this microfluidic chip. The title of this image is inspired by Claude Monet’s Impression Sunrise.


Widmer Poster Prize
The Widmer Poster Prize was awarded this year to Sohyung Lee (UCLA, USA), for her poster and video presentation on “Scalable fabrication of 3D structured microparticles using induced phase separation”. Sohyung put a huge amount of time and effort into her presentation, and the judges were very impressed.


Congratulations to all the winners at this year’s hybrid µTAS conference. We look forward to seeing you at µTAS 2022 (Hangzhou, China)!

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 thematic collection open for submissions – AI in Microfluidics

We are delighted to announce a new thematic collection in Lab on a Chip on AI in Microfluidics, with Professors Keisuke Goda, Hang Lu, Peng Fei & Jochen Guck as Thought Leaders.

 

 

The last decade has seen unprecedented growth in computational power and cloud storage breakthroughs in artificial intelligence (AI). AI-produced outcomes have been proven comparable or even superior to the performance of human experts in drug design, material discovery, and medical diagnosis. In these applications, lab on a chip technology, in particular microfluidics, plays an important role as a platform for both the construction and implementation of AI in a large-scale, high-throughput, automated, multiplexed, and cost-effective manner. The goal of this thematic collection is to highlight new advances in this growing field with an emphasis on the interface between technological advancements and impactful applications.

This on-going collection is collated by Thought Leaders Keisuke Goda, Hang Lu, Peng Fei & Jochen Guck, and the Lab on a Chip Editorial Office. Are you interested in submitting? We welcome submissions of original research articles and reviews, which (after peer review) will be published and added to the online collection. Papers in this collection will receive extensive promotion throughout the submission period and also will be disseminated widely as a ‘flagship’ collection for the journal. If you are interested in submitting to the series, please get in touch with the Lab on a Chip Editorial Office at loc-rsc@rsc.org

This collection open for submissions now, with a deadline of April 1st 2022

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 on a Chip and Dolomite 2021 Pioneers of Miniaturization Lectureship Winner

Lab on a Chip and Dolomite are delighted to announce the winner of the 2021 Pioneers of Miniaturization Lectureship, Professor Keisuke Goda.

This Lectureship honours and supports the up and coming, next generation of scientists who have significantly contributed to the understanding or development of miniaturised systems.

Keisuke Goda is a professor in the Department of Chemistry at the University of Tokyo, an adjunct professor in the Institute of Technological Sciences at Wuhan University, and an adjunct professor in the Department of Bioengineering at UCLA. He obtained his B.A. from UC Berkeley summa cum laude in 2001 and his Ph.D. from MIT in 2007, both in physics. At MIT, he worked on the development of gravitational-wave detectors in the LIGO group which led to the 2017 Nobel Prize in Physics. After several years of work on high-speed imaging and microfluidics at Caltech and UCLA, he joined the University of Tokyo as a professor. His research group focuses on the development of serendipity-enabling technologies based on molecular imaging and spectroscopy together with microfluidics and computational analytics to push the frontier of science. He currently leads Serendipity Lab, a global network of scientists who aim to realize Louis Pasteur’s statement “Chance favours the prepared mind”. He has published >300 papers, filed >30 patents, and received numerous awards and honours such as Japan Academy Medal and JSPS Prize. He is a fellow of RSC and SPIE.

 

Our Pioneers of Miniaturization Lectureship Winner is invited to speak at MicroTAS, and thus Keisuke will be presenting his talk at the MicroTAS 2021 meeting, 10-14th October 2021.

We give our warmest congratulations to Keisuke on his achievement!


Read some of Keisuke Goda’s recent Lab on a Chip papers* below:

Are droplets really suitable for single-cell analysis? A case study on yeast in droplets

Y. Nakagawa, S. Ohnuki, N. Kondo, K. Itto, F. Ghanegolmohammadi, A. Isozaki, Y. Ohya, and K. Goda, “Are droplets really suitable for single-cell analysis? A case study on yeast in droplets”, Lab on a Chip, 19, 3793, (2021)

AI on a chip

A. Isozaki, J. Harmon, Y. Zhou, S. Li, Y. Nakagawa, M. Hayashi, H. Mikami, C. Lei, and K. Goda, “AI on a chip”, Lab on a Chip, 17, 3074 (2020)

Intelligent image-activated cell sorting 2.0

A. Isozaki, H. Mikami, H. Tezuka, H. Matsumura, K. Huang, M. Akamine, K. Hiramatsu, T. Iino, T. Ito, H. Karakawa, Y. Kasai, Y. Li, Y. Nakagawa, S. Ohnuki, T. Ota, Y. Qian, S. Sakuma, T. Sekiya, Y. Shirasaki, N. Suzuki, E. Tayyabi, T. Wakamiya, M. Xu, M. Yamagishi, H. Yan, Q. Yu, S. Yan, D. Yuan, W. Zhang, Y. Zhao, F. Arai, R. E. Campbell, C. Danelon, D. Di Carlo, K. Hiraki, Y. Hoshino, Y. Hosokawa, M. Inaba, A. Nakagawa, Y. Ohya, M. Oikawa, S. Uemura, Y. Ozeki, T. Sugimura, N. Nitta, and K. Goda, “Intelligent image-activated cell sorting 2.0”, Lab on a Chip, 13, 2263 (2020)


*Free to read until 31st October 2021 with an RSC publishing account.

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)

Emerging Investigators in Microfluidics Conference (EIMC) · 20-21 July 2021

The online conference on Emerging Investigators in Microfluidics Conference (EIMC) will take place from Tuesday 20th to Wednesday 21st of July 2021, starting at 8:00 EDT- Boston Time/ 13:00h UTC/14:00h CEST-Amsterdam-Madrid.


 Emerging Investigators in Microfluidics Conference (EIMC)In the last 30 years, the field of microfluidics has transitioned from infancy to an established discipline with diverse applications being explored by an equally diverse community of scientists and engineers. The field has matured to a state where researchers can buy off-the-shelf microfluidic equipment (chips, pumps, flow meters etc.) and microfluidic componentry is standard within numerous different commercialized analytical and diagnostic devices. However, the continued development of the field depends on the supply of fresh innovative ideas and the nurturing of new leaders within the field.

This meeting aims to showcase work from the next generation of microfluidics researchers (specifically academics/researchers in permanent positions of less than ~6 years, and earlier career stages). The meeting will provide an opportunity to discuss recent developments in the field and develop future research opportunities as part of an overall aim to nurture and promote the careers of emerging researchers within the international microfluidic community.

The conference will run over two days and feature sessions focusing on three “hot” areas of microfluidics: synthetic biology (artificial cells, organ on a chip), portable devices (point-of-care diagnostics, in-the-field analysis), and bioanalysis (single cell analysis, nucleic acid analysis). Oral sessions will feature presentations by invited speakers, in addition to presentations selected from submission of abstracts. There will be a session for researchers to present posters, with additional networking opportunities.

Conference Organisers

Topics to be covered by the conference:
  • Other areas of microfluidics
  • Single cell analysis
  • Diagnostics
  • Analytical chemistry/biochemistry
  • Synthetic biology
  • Artificial cells
  • Organs on a chip

Key Dates

Abstracts submission deadline (oral): 28th June 2021
Abstracts submission deadline (poster): 15th July 2021
Scientific program: 2nd July 2021

Useful Links

Register your attendance for the conference here

Learn more about the conference details here

Look at the conference schedule here

 

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)

Interview with Editor-in-Chief Aaron Wheeler

Aaron Wheeler, Editor-in-Chief of Lab on a Chip, discusses challenges in microfluidics, exciting advancements and the future of the field.


1. What attracted you to pursue a career in microfluidics and how did you get to where you are now?

I did my Ph.D. in chemistry working with Richard “Dick” Zare at Stanford University. I planned to work on projects related to capillary electrophoresis, but shortly after I started, Dick introduced me to a postdoc, Keisuke Morishima (now a professor at Osaka University), who was working in the then ‘new’ area of microfluidics. A few trips to the cleanroom later, I was hooked, and spent my time as a graduate student developing microfluidic methods to analyze the contents of single cells. After completing my Ph.D., I went to work as a postdoc with Robin Garrell at UCLA, where I learned about the technique known popularly as “digital microfluidics.” Robin introduced me to Chang-Jin “CJ” Kim and Joe Loo, and I spent two years working with those three labs, developing interfaces between microfluidics and mass spectrometry. I then moved to Canada to begin my career as an academic at the University of Toronto, where my research group and I continue to explore how microfluidics can be used to solve problems in chemistry, biology, and medicine. I will note that being an academic is great fun, but the popular perception of this job is wrong. Most readers of this piece (presumably) understand this, but I am always amazed when I talk to people outside of academia who assume that it is the professors who have the ideas, run the experiments, collect the data, interpret the results, and write the papers. Of course, this is not true at all – these things are primarily done by students and postdocs! The opportunity to work with energetic, creative, and hard-working young people is what makes this job so much fun.

 

2. What do you see as the biggest challenges facing researchers who work in your field?

There are of course myriad technical challenges in the Lab on a Chip community, but after observing many cycles of research in this field, I am convinced that technical challenges that arise are almost always ultimately solved – a testament to the incredible ingenuity of Lab on a Chip researchers. One non-technical challenge is the gap between what is claimed and what is demonstrated in scientific papers. We researchers experience great pressure to ‘sell’ our work, which occasionally leads us to make claims that surpass what is demonstrated. I urge my colleagues to try to resist this temptation, as it sets up problems down the road! For example, if I publish results A but claim that they are B, when another group comes along to report actually doing B, inexperienced editors and reviewers may point to the previous paper to say that the work is not novel because B has already been done! One of the great things about working with Lab on a Chip is that we have the best editors and reviewers in the world – they are knowledgeable, sophisticated, and experienced, and can (in the vast majority of cases) sniff out differences between what is shown and what is claimed. But the gulf between what is claimed and what has been demonstrated exists, which makes reviewing more challenging than it need be, and I see it having negative impacts in other settings with reviewers and editors who are not as experienced as ours.

 

3. What is the most exciting research paper that you have read recently? Which of your publications are you most proud of?

I will highlight two interesting papers from recent issues of Lab on a Chip. On the ‘fundamentals’ end of the spectrum, Binsley et al. (Lab Chip, 2020, 20, 4285-4295) described a remarkable system in which an oscillating magnetic field was made to drive the movement of a stretchable PDMS structure to control the flow direction and flow rate in a microfluidic device – a unique, self-contained “pump.” Meanwhile, on the ‘applied’ end of the spectrum, Sun et al. (Lab Chip, 2020, 20, 1621-1627) described an integrated device that amplifies viral nucleic acid sequences in swab eluent with smart-phone detection for point-of-care diagnosis – a clear example of the role our community is playing in responding to the global pandemic.

For my own publications, I am proud of them all/they are all my favourites (like my children)! If you force me to choose one, I would likely point you to our 2019 paper that described the technical challenges (and solutions to those challenges) that we encountered in our work interfacing digital microfluidics with NMR spectroscopy (Lab Chip, 2019, 19, 641-653). It is not our flashiest work, but (like a boxer) it represents some of the hardest work “pound for pound” that my lab has done, coming up with solutions to initiate, control, and monitor chemical reactions in sub-microliter samples in the bore of the superconducting magnet deep inside a high-resolution NMR spectrometer.

 

4. What career would you have chosen if you had not taken this career path?

I am absolutely jealous of my colleagues who are professors in the Lab on a Chip community by day and celebrated jazz musicians (or gourmet chefs, or football champions, etc.) by night. Unfortunately, I am not one of those people, and particularly since having children, family and work occupy nearly all of my time. This is amplified during these days of pandemic – like everyone, I am eager for the vaccines to roll out so that we can move to the next phase of our lives!

 

5. What do you see as the most important scientific achievement of the last decade? Why should young people study chemistry?

This decade has seen a steady stream of incredible advances (in our field and in others), but if I had to choose one, I would point to the single-cell genome/transcriptome sequencing revolution. The idea of single-cell sequencing is not a new one to Lab on a Chip readers, but the revolution went “mainstream” in 2015 when Lab on a Chip Advisory Board member David Weitz published seminal papers describing strategies to label cells with unique barcodes in droplets in microchannels (Cell, 2015, 161, 1187–1201; Cell, 2015, 161, 1202–1214), which captured the attention and imagination of researchers around the world. Companies working with related/complementary technologies got in the game (including most notably, 10x Genomics https://www.10xgenomics.com/) and the rest, as they say, is history – single-cell sequencing is now an almost routine technique in the biology lab. I encourage you to check out Weitz’s 2017 editorial on the subject (Lab Chip, 2017,17, 2539), and more generally, the associated collection of papers of papers in Lab on a Chip. It is always fun to see technologies from the Lab on a Chip community go mainstream, and I hope this is something that the journal can help promote more of in the years to come.

You also asked why young people should study chemistry, which is a great question. Chemistry is known as the ‘central science’ because it underpins nearly every part of the world that we touch, see, smell, and hear, and taste – it is thus a natural fit for anyone who is curious about the world around them. But as a matter of principle, I always encourage young (and young-at-heart) people to think outside the boundaries of disciplines to explore the world while wearing whatever disciplinary “hat” is needed to address the most interesting questions at hand. That’s one reason why I love being a part of the Lab on a Chip community. One can pick up any issue (I am choosing volume 20, issue 24, for these examples) to find papers from biomedical engineers (Lab Chip, 2020, 20, 4561-4571), chemists (Lab Chip, 2020, 20, 4632-4637), chemical engineers (Lab Chip, 2020, 20, 4528-4538), electrical engineers (Lab Chip, 2020, 20, 4582-4591), materials scientists (Lab Chip, 2020, 20, 4572-4581), mechanical engineers (Lab Chip, 2020, 20, 4512-4527), and many others.

 

6. What are you most looking forward to in your new role as Editor in Chief for LOC?

I love this journal. My mission as Editor-in-Chief is to work with our amazing team of Associate Editors to remind the community that Lab on a Chip is a great ‘home’ for the most important work that is being done in the field. We look forward to seeing your next submission!

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)

Avoiding air bubbles when filling microfluidic chips by use of an ultrasonic bath

Leonie Bastin1 and Karen Alim1,2

1 Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany

2 Physics Department, Technical University of Munich, Germany

Why is this useful?

In microfluidic devices with small structures, air bubbles are often trapped at interfaces, corners or structures within the channel. The presented method is reproducible, fast, and only requires an additional ultrasonic bath. Vibrations from the ultrasonic bath detach the bubbles from surfaces. By flushing the chip with water at the same time, the bubbles are transported out.

What do I need?

  • An ultrasonic bath
  • The microfluidic device
  • A syringe filled with water

What do I do?

  1. Connect the syringe to the microfluidic device.
  2. Lay the device into the ultrasonic bath and turn it on.
  3. Manually fill the device with water, varying the pressure in pulses of around a second in length (see inset in Figure 1A). Use high flow rates! In our case, we used flow rates of approximately 50 microliters per second during the pulses.
  4. Before the syringe is empty, turn off the ultrasound bath, take the device out and check whether there is any air left in the channel.
  5. If there is air left in the chip, press some water through with high speed when the device is not laying in the ultrasound bath.
  6. If there are still bubbles left, repeat the procedure.
  7. Once no bubbles are left in the chip, insert the syringe for your experiment on the other side of the chip. To avoid the appearance of new bubbles, press out some of the liquid so that a drop appears at the outlet before you insert the syringe.

 

Figure 1: (A) Schematic drawing of the setup. The tubing at the outlet is optional if you fill the chip with water. The manual pressure pulses are sketched in the inset. (B) Photo of the setup without tubing at the outlet. (C) Fluorescence microscopy image of a chip filled with fluorescein to visualise the structure that is shown in D and E only filled with water. The center part is filled with 100 micrometer wide PDMS-pillars, which are arranged in a hexagonal structure. (D) Photo of a small region of the chip when filled with water without using the ultrasound method. Many air bubbles are visible between the pillar structures (arrows). (E) Photo of the same region after using the ultrasound method. No air bubbles are left in the chip.

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)

Pioneers of Miniaturization Lectureship 2021

Lab on a Chip and Dolomite are proud to sponsor the sixteenth Pioneers of Miniaturization Lectureship, to honour and support the up and coming, next generation of scientists who have significantly contributed to the understanding or development of miniaturised systems.


This year’s Lectureship will be presented at µTAS 2021 with the recipient receiving a prize of US$3,000.

The Lectureship consists of the following elements:

  • A prize of US$3,000. No other financial contribution will be offered
  • A certificate recognising the winner of the lectureship
  • The awardee is required to give a short lecture at the µTAS 2021 event

Eligibility Criteria

To be eligible for the lectureship, candidates must:

  • Have completed their PhD
  • Be actively pursuing an independent research career on miniaturised systems.
  • Be at an early-mid career stage of their independent career (typically this will be within 15 years of completing their PhD, but appropriate consideration will be given to those who have taken a career break or followed a different study path).

Nomination process

To be considered for the 2021 lectureship, the following must be sent to the Editorial Office

  • A letter of recommendation with the candidate’s accomplishments and why the lectureship is deserved.
  • The nominee must be aware that he/she has been nominated for this lectureship.
  • A complete nomination form (includes list of the candidate’s relevant publications or recent work, candidate’s scientific CV, and full contact details)
  • Nominations from students and self-nominations are not permissible.

Selection criteria and judging process

  • Nominations must be made via email to loc-rsc@rsc.org using the Dolomite/Lab on a Chip Pioneers of Miniaturization Lectureship nomination form and a letter of recommendation.
  • The decision on the winner of the lectureship will be made by a panel of judges comprising a representative from Dolomite and members from the Lab on a Chip Editorial Board, coordinated by the Executive Editor of Lab on a Chip.
  • The award is for outstanding contributions to the understanding or development of miniaturised systems. This will be judged mainly through their top 1-3 papers and/or an invention documented by patents/or a commercial product. Awards and honorary memberships may also be considered.

Update: The nomination deadline has been extended from 31st May 2021 to 30th June 2021.

Nomination Deadline: 30 June 2021


Download Nomination form here 

Dolomite Microfluidics a leading provider of microfluidics-based solutions for a range of applications including drug encapsulation, droplet manufacture and particle generation. They manufacture complete systems as well as individual modular components to balance ease of use with flexibility.

 

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)

Emerging Investigator Series – Aaron Streets

Lab on a Chip is very excited to introduce our most recent Emerging Investigator, Dr Aaron Streets! 

Aaron received a Bachelor of Science in Physics and a Bachelor of Arts in Art at the University of California, Los Angeles. He completed his PhD in Applied Physics at Stanford University with Dr. Stephen Quake. Aaron then went to Beijing, China as a Whitaker International Postdoctoral Fellow and a Ford postdoctoral fellow and worked with Dr. Yanyi Huang in the Peking University BIOPIC institute. Aaron joined the faculty of the University of California, Berkeley as an Assistant Professor in Bioengineering in 2016. He is currently a core member of the Biophysics Program and the Center for Computational Biology and he is a Chan Zuckerberg Biohub investigator. Aaron has received the NSF Early Career award and was recently named a Pew Biomedical Scholar.

You can read Aaron’s article, μCB-seq: microfluidic cell barcoding and sequencing for high-resolution imaging and sequencing of single cells, here.

If you’d like to know more about Aaron and his research, read the short interview with him below!


Your recent Emerging Investigator Series paper focuses on microfluidic cell barcoding and sequencing. How has your research evolved from your first article to this most recent article?

My first publication used a microfluidic-based dynamic light scattering apparatus to investigate protein crystallization. While this study relied on the integration of microfluidic control and optical analysis, it was really focused on the physics of biological macromolecule phase transitions. No cells, no sequencing, not even any microscopy.  The continuous thread that has persisted through my research has been the integration of multilayer microfluidic circuits with advanced optical analysis techniques, however we now take advantage of this technology to study single cells. This means that we rely on a lot of additional experimental and computational tools upstream and downstream of the microfluidics, including interfacing directly with biological samples that are input into our devices, as well as the library preparation, high-throughput sequencing, and ultimately genomic data analysis that are essentially the device outputs. So, while “lab-on-chip” technology is still at the core of our research, we rely heavily on a “chip-in-a-lab” paradigm.

What aspect of your work are you most excited about at the moment?

After a decade-and-a-half of working with microfluidic technology it is extremely energizing to see microfluidics percolate into all corners of biology and the biomedical sciences. It is particularly exciting to see microfluidic platforms become the primary driving technology that has advanced the field of single-cell biology. From the integrated microfluidic circuits that provided the first commercial single-cell RNA-seq platforms, to the droplet microfluidics and microwell technology that has brought ultra-high-throughput single-cell genomics to the masses and has fuelled the Human Cell Atlas Project. In our lab, we are excited about taking a deeper dive into single-cell measurements, and instead of optimizing throughput, really pushing the information content that can be extracted from a single cell. One of the beautiful aspects of integrated microfluidic circuits is that they pair incredibly well with advanced microscopy techniques while facilitating single-cell manipulation and sequential molecular biology protocols. We are excited about using these capabilities to make multimodal measurements on single cells, connecting genomic information to the spatial organization of molecules and other morphological phenotypes that are probed more efficiently with light.

In your opinion, what is the biggest advantage to using the μCB-seq platform compared to other methods?

It is easy to take a high-resolution image of a single cell, and it is easy (nowadays) to amplify and sequence the RNA or DNA from a single cell. It is still challenging, however, to take a high-resolution image of a single cell, and then pluck that same cell from the microscope slide and sequence it.  Microfluidic cell barcoding and sequencing (μCB-seq) provides a way to do just that for many cells in parallel. With this platform, we are really just using microfluidic chambers to help keep track of which cell was imaged before sequencing. To make this work, we use DNA barcodes that are pre-loaded into the microfluidic device so that each single-cell imaging chamber gets a unique cell barcode. After imaging each cell, that unique barcode gets imprinted into the cDNA from each respective cell so that we can pool all the cDNA from the lanes of our device and make a single sequencing library. After sequencing, the barcode will tell us which transcripts came from which cell, linking gene expression to image data.

What do you find most challenging about your research?

The most challenging aspects of our work tend to be figured out by the PhD students. These are the details you can’t find in a textbook like how to make a device robust to thermal cycling while under a microscope, or where did the cDNA go, or why isn’t this thing working? The truth is that there is a significant up-front investment in resources and time to get these platforms functional. Furthermore, depending on the type of microscopy, many of these tools cannot be ported into other labs. Once we get something like μCB-seq to the proof-of-principle stage there is another set of obstacles to make it a robust technology that we can train collaborators to use efficiently, so that the technology can have impact. Getting these tools into the hands of people who want to use them is still a non-trivial challenge, especially as the front-end and back-end of these experiments require more and more equipment and expertise. 

At which upcoming conferences or events may our readers meet you?

I would love to see everyone at the Physics and Chemistry of Microfluidics Gordon Research Conference in 2021. But if we can’t see each other in Tuscany, I look forward to seeing you on Zoom!

How do you spend your spare time? 

These days? Good question. I enjoy reading science fiction. I am an avid basketball fan. I love listening to live music. So I guess the answer is… reading science fiction.

Which profession would you choose if you were not a scientist?

I would be a world-famous artist. (Are we allowed to choose how successful we would be? Or just the profession?) Ok, I would be an artist… and a bartender. I studied art in undergrad at UCLA and I always imagined an alternate career making paintings and sculptures and art installations. 


If you’re interested in other articles in our Emerging Investigator Series, the whole collection can be found here

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)

Digital microfluidics for handling picoliters

Just another day at the chemistry lab. Get in, make sure to wear PPE thoroughly, grab a pipette set, start reading, and applying the steps of the experiment. Pipette hundreds of microliters of a solution, done. Pipette tens of microliters of another solution, no problems. Pipette several picoliters of …, what? Wait!  Can we pipet sub-microliter size liquids? The answer will be yes at this time, but we will twist it a bit. As the name suggests, microfluidics is the art of handling tiny amounts of liquids. Can it be helpful when it comes to handling sub-microliter size droplets?

Since the early 2000s, digital microfluidics (DMF) has been proposed as a more versatile candidate in sample processing applications. Most DMF devices use electric field application to control the displacement of droplets, which are separated from the underlying electrodes via a dielectric layer and an nm-thick hydrophobic layer. Once we actuate an electrode, the contact angle, and in turn, the hydrophobicity, of a droplet sitting on top of the electrode decreases due to surface energy changes. This would be a golden moment because if we actuate a neighboring electrode now, the droplet will displace towards the activated electrode. Based on this principle, we can transport, dispense, merge, and split droplets in a digital microfluidic platform.

One constraint of current digital microfluidic systems is that droplet volume is limited by electrode area. Droplets can only be reliably split and displaced above a certain volume as they will not be capable of displacing towards another electrode if their contact area is too small. Working with smaller scale electrodes does not solve the problem either, but it makes evaporation-related problems more pronounced.

In the recent Lab on a Chip article of researchers from the University of Macau (CN) and the University of Lisboa (PT) demonstrated the controllable ejection of satellite droplets to create a digital microfluidic platform that is capable of transporting picoliter-volume droplets. Precise control of ejection position and volume was made possible using a narrow electrode, or a jetting bar, which focused the area of high voltage AC actuation. During a rapid change in electric field intensity beyond the contact angle saturation threshold voltage, the excess energy is released by the ejection of satellite droplets. The dispensing droplet would release picoliter sized volumes onto the jetting bar which were then collected by another droplet moving over the jetting bar (Fig. 1). Volumes between 5 pL to 20 nL can be produced by repeatedly dispensing and collecting picoliter-size droplets at the jetting bar. The dispensed volume could also be controlled by changing increasing the width of the jetting bar for greater volumes. Dispensing volume can also be carefully controlled by the strength of the electric field, the actuation frequency, and actuation time.

The authors showed that the picoliter- volume dosing system can be used in a dequenching assay. Fluorescent DNA probes specific to S. aureus were delivered to droplets containing S. aureus and K. pneumonia using this assay. The dispensed satellite droplets successfully delivered the DNA probes to the droplets. The authors built a quantitative relationship between the degree of fluorescence and volume delivered in the S. aureus droplet accordingly. The authors think that this new technique may make microfluidics more accessible in sample preparation for clinical and lab studies in the future.

Figure 1. The dispensing drop releases satellite droplets under high voltage AC actuation of the jetting bar. The satellite droplets are then taken up by another droplet, facilitating volume transfer without the merging of either the dispensing or pickup-up droplet.

 

To download the full article for free* click the link below:

Turning on/off satellite droplet ejection for flexible sample delivery on digital microfluidics

Haoran Li, Ren Shen, Cheng Dong, Tianlan ChenYanwei Jia, Pui-In Mak and Rui P. Martins, Lab Chip, 2020, Lab on a Chip Hot Articles

DOI: 10.1039/D0LC00701C

 

About the Webwriters

Burcu Gumuscu is an assistant professor in BioInterface Science Group at Eindhoven University of Technology in the Netherlands. She strives for the development, fabrication, and application of smart biomaterials to realize high-precision processing in high-throughput microfluidic settings. She specifically focuses on the design and development of lab-on-a-chip devices containing hydrogels for diversified life sciences applications. She is also interested in combining data-mining and machine learning techniques with hypothesis-driven experimental research for future research.

 

Miguel FaaseMiguel Faase is a Ph.D. student in BioInterface Science Group at Eindhoven University of Technology in the Netherlands. He focuses on the development of high-throughput screening platforms for biomaterial research under the supervision of Burcu Gumuscu.

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)