At a Glance
Name: Emmanuel Delamarche
Title: Research Scientist, IBM Research, Zurich Research Laboratory
Professional Background: Delamarche has been a researcher at IBM for over a decade. He currently leads research on self-assembly, soft lithography, surface chemistry, electroless deposition of metals, microfluidics, the patterning of biological molecules, miniaturized biological assays, diagnostics, and nanotechnology at the firm's Zurich Research Laboratory.
Education: 1992 BSc in supramolecular chemistry, University Paul Sabatier of Toulouse, France; 1995 PhD in biochemistry, University of Zurich.
IBM has always had a strong presence in the array market as an informatics provider. But it may come as a surprise to some to learn that the informatics giant recently discovered and published a new method that can be used for spotting protein arrays.
Published in this month's issue of Nature Materials by IBM scientists Emmanuel Delamarche, David Juncker, and Heinz Schmidt who are based at the firm's Zurich Research Laboratory in Switzerland, the article, titled "Multipurpose Microfluidic Probe," describes a new method for spotting proteins, cells, and other biological molecules of interest to researchers.
In short, the method developed by IBM allows researchers to spot proteins in their home environment, by using a spotter submerged in a standard buffer that prints the arrays below the surface of the buffer, allowing the proteins to remain in an intact, natural state. While IBM has no immediate plans to commercialize the method, it is willing to license it, according to officials. To get a better handle on how the new method works BioArray News spoke with author and IBM researcher Emmanuel Delamarche last week.
Why did you see a need to create something like this?
In general our work is centered on creating techniques that can process patterns, reoccurring patterns, microtechnology, soft lithography things that are very important for our technology in IBM.
We are always interested in developing these technologies, but we also take the opportunity when we develop a precise patterning technique to make it applicable to problems or challenges in biology.
So in this case our motivation was that we do not have the regular tools for patterning proteins locally on the surface of a substrate to investigate one cell, a single cell, for example.
And one of the premises is that you have a lot of tools in microtechnology, but they can be very harsh on biological material, they have radiation, UV, high temperature and so on. And anything that is gentle with biological material is always very interesting.
So in this case we are really interested in looking at how microfluidic devices for patterning surfaces could be applicable to pattern proteins [and] manipulate cells. What is important, is that proteins and cells most of the time aren't [pleased] to be in a dry space.
Most of the time we have used microarrays, protein arrays, and so, people spot using a jet to shoot a nanoliter or picoliter of liquid on a surface and so then most of the liquid evaporates and leaves on the surface multi-layers of a kind of protein. We thought it would be really ideal to develop a type of patterning microfluidic technology that can deliver small volumes of proteins on a surface but where we would use the technique and delivering method with a surrounding liquid.
Can you explain how you spot onto the substrate in this liquid environment?
Imagine that the device looks like a pen. The tip of the pen has two apertures. One aperture ejects a continuous flow of liquid, and there is a second aperture near by that aspirates back the liquid that is ejected by the first aperture.
But now imagine that this pen is writing on a piece of paper, and you have water all around. So you have a pen that works under water that can write on a surface. So the way it works is that the liquid flows from one aperture to the other and on the flow path there is a contact between this writing liquid and the surface and in the zones of contact you can for example, deposit proteins on the surface, but you can also use this flowing liquid to actually aspirate by friction if you like a single cell from the surface back into the pen.
You mentioned that this device is also useful for spotting protein arrays. Can you explain how your method for spotting protein arrays works and how it compares to current methods?
Typically proteins like to deposit in solutions onto surface, and in particular onto hydrophobic surfaces it's a natural, spontaneous event. So you don't really need to do anything special in terms of chemistry.
What you want to do then is to simply bring the solutions of proteins locally in contact with the surface. And the proteins will spontaneously diffuse and bind when coming into contact with the surface and make a spot.
The key is to localize the solution of proteins onto a small region on the surface.
What kind of surface are you using?
We have used plastic so planar surfaces, because if you were to write on something that is very corrugated or something that has an uneven surface you might crash the device into an obstacle, but say glass slides for example, or plastic laminates, all of those are good substrates. You can write on silicon wafers and so on. The roughness is not actually very important. We were able to write patterns on surfaces that were chemically treated to bind better with proteins. So you can also use surfaces that are prepared with certain chemicals.
How many can you print at a time?
What is the most important thing is that there is no drying, there is no air. So at no point during the spotting of the protein do you have to deal with a drying effect. And drying is very problematic because it leads to having very [immobilized] volumes on a surface.
Another important thing is that we work under microfluidic conditions. The diffusion of proteins on the micrometer scale can be very fast. A protein can travel a micrometer distance within a millisecond. So the first technique is extremely fast. You can make one spot of protein within a few milliseconds.
And you use very little volume. Typically we speak about 100 picoliters of solution to make a small array. So it's very, very economical with solution.
Typically we can only spot a few proteins down onto a surface, but the resolution and the homogeneity of the sites are very high. So you would have to say our technique would be very useful when people are interested in having high quality protein sites on a surface.
But is there any plan to commercialize the method?
I would say it is not our direct intention to commercialize. The main goal our research project is mostly to develop a toolbox for structuring surfaces. But typically, like in this example, if a partner which could be a university or a company would find an interest in using it, we always can pass on a license and work with end users for example. It is not typical for us to try directly to commercialize microfluidics or this type of technology in the market.