Tag Archives: lab

Making Your Experiments Easier to Digest

One of the great things about being a science journalist is being among the first to hear about technologies that are cool, useful, and/or downright weird. Today, for example, I learned that the world’s leading manufacturer of artificial laboratory stomachs has released a fascinating new series of videos. You can check out their channel on YouTube, where you’ll find such gems as this brief instructional piece that covers – quite literally – the care and feeding of your artificial laboratory stomach:

Sewing a Lab Chip

Lab-on-a-chip devices are a hot topic these days, and more and more researchers are finding cheap ways to make these tiny devices (see my earlier posts on these cool tools for background). Now, some Australian scientists have taken the process into the arts and crafts department:

This paper describes a new and simple concept for fabricating low-cost, low-volume, easy-to-use microfluidic devices using threads. A thread can transport liquid via capillary wicking without the need of a barrier; as it is stainable, it is also a desirable material for displaying colorimetric results. When used in sewing, threads have 3D passageways in sewed materials. The wicking property and flexibility of thread make it particularly suitable to fabricate 3D microfluidic devices. Threads can also be used with other materials (e.g., paper) to make microfluidic devices for rapid qualitative or semiquantitative analysis. These thread-based and thread-paper-based devices have potential applications in human health diagnostics, environmental monitoring, and food safety analysis, and are particularly appropriate for the developing world or remote areas, because of their relatively low fabrication costs.

They’re not kidding about the low fabrication costs. In the paper, they stitched some simple “devices” out of ordinary cotton thread and paper. They did “de-wax” the thread in a vacuum plasma reactor, which most folks probably don’t have sitting around, but there could be other ways of accomplishing that step. The other limitation is that the threads average 244µm in diameter, which is a good bit fatter than the features in a typical commercial lab chip. Maybe we could call these “millifluidic” devices instead of “microfluidic.”

Still, it’s a very cool idea, and it could have some unusual applications. Now if you’ll excuse me, I have to go stitch up a salmonella-detecting dish cloth.

Cell Is for Cellulose

Cultured cells are a mainstay of modern biomedical research, but they’re very limiting. Growing the cells in a flat monolayer on a petri dish is the easiest way to control and study them, but it doesn’t represent their normal in vivo environment. Culturing them in a 3-dimensional matrix encounters the other horn of the dilemma: the cells are growing in a structure more like a real tissue, but they’re much harder to maintain.

Now, the prolific lab of George Whitesides has hit on an astonishingly simple and cheap solution:

Ratmir Derda, a postdoctoral student co-mentored by Whitesides and [Don] Ingber at Harvard’s new Wyss Institute for Biologically Inspired Engineering, has realized that by growing cells on several sheets of uncoated paper, he can solve a problem that has bedeviled biologists for years: how to easily grow and study cells that mimic the three-dimensionality of real tissue.

3D image of epithelial cells growing on cellulose. Image courtesy Ratmir Derda.

3D image of epithelial cells growing on cellulose. Image courtesy Ratmir Derda.

You read that right: paper. They’re taking plain sheets of blotter paper, sterilizing them, and dipping them in a cell-impregnated nutrient gel. They can then fold or layer the paper to create whatever 3-dimensional structure they like, all while maintaining the accessibility and reliability of flat cultures.

The work supposedly appeared in the 19 October issue of PNAS, but I can’t find it on the journal’s web site. Hopefully they’ll put it online soon, because I’m sure there are a whole lot of cell biologists waiting to try this out in their own labs.