3D Printing stuff for your lab, hype and realities

Published: April 11th, 2016   Last Modified: June 16th, 2017

3D printing as a technology has been around for decades, with makers and hackers making 3D printers economical for consumers only in the last 5 years or so. There’s more than one way to frikassee a cat, just as there’s more than one way to 3D print an object. Rather than cover the plethora of emerging 3D printing technologies, I will talk about what is known as fused deposition modeling (FDM). Essentially, you have a plastic filament pulled into a heated nozzle (Think of an arts and crafts glue gun) which is able to move in the X, Y and Z axis. The movement of the nozzle is controlled by a computer interface where you put your digital 3D model. Software converts the 3D model into X, Y and Z movements the printer can understand and off it goes!

There’s been a bit of buzz about 3D printing lab equipment and I thought I’d weigh in with my experiences, both good and bad so that you can decide whether it’s worth getting one for your lab.

I bought my own 3D printer several years ago now (~500$), a design derivative of the reprap that I use to print mainly with poly lactic acid (PLA) filament. Ever since setting foot in the lab my mind began racing with ideas of how to make things more efficient and easier, so the 3D printer, which can print almost any object, was a perfect companion for prototyping.

Before I could get started printing anything I had to assemble the machine. For someone not at all familiar with mechanical engineering this took several days. If you pay more, you can get one assembled, but honestly you will be tearing it apart so often you may as well assemble it yourself so you can learn how every part works. So, time invested into assembly, okay.

Once assembled, the next step was to actually print something. The software side of things wasn’t that bad, and my toolchain is basically Google sketchup -> Export to STL -> Load into repetierhost -> print. Easy, right? WRONG! If you press print on a freshly built 3D printer you will be lucky to get a molten blob on your build platform. One major problem of consumer grade 3D printing is calibration and adjustment. You tell the printer to move 100 mm in the X axis, but how does it know how far 100 mm is? You have to tell the motors exactly how many steps 100 mm is. Then check it moves that much. Check again. Same story with the nozzle, how much filament should it be dispensing? How hot should it be? How do I get my bloody print to stick to the build platform??? More tweaking. See a pattern? Anyway, learning how to calibrate the printer so it could actually print something useful took the better part of a month, with a few hours here and there when I had downtime from my experiments.

Herein lies one major issue with integrating 3D printing into your lab and that is time investment. Setting up a 3D printer, learning how to calibrate it, learning basic 3D modeling, adjusting it, tweaking it when things go wrong (which is often) all takes time. I am blessed in that I have a supervisor who let’s me express my creativity on my downtime, which I repay by making useful things for the lab. I realize not every supervisor is like that. To truly integrate 3D printing into your lab you would essentially need to hire someone who is willing to tweak and optimize all day long. Unfortunately that person would then be unavailable to perform lab experiments, which net publications, which are a labs bread and butter. The benefit of saving a few hundred or perhaps a few thousand dollars by printing your own equipment has to be weighed against productivity.

Pessimistic realism aside, let’s take a look at some of the gadgets, widgets and weird items I’ve made that benefit the lab.

Electrophoresis Gel Combs

One of the first objects that I made were combs for running agarose gels. The pink ones I actually paid to get printed at Shapeways and they’ve held up quite well (Although they cost more and use sintering technology). The other combs were printed on my humble little printer. Generally speaking they work reasonably well, and being able to have a custom comb in under an hour is handy. Here are some things to watch out for though. PLA plastic varies in it’s properties from batch to batch, so while some may hold up well over time, others will not. The hot, moist environment of a gel tray causes the PLA to get brittle and teeth will pop off and bend. The layering effect of the 3d printer leaves a rough finish which you need to smooth with sandpaper + a bit of chloroform (Yep), otherwise you’ll take off chunks of your well when you pull out the comb. I have experimented with different materials (ABS, PETG) however none of them really last for more than a few months. To be fair, I’m a firm believer that life is too damn short to wait for your agarose to cool. In the end I’m shying away from printing combs, what I’ve found works best are custom, artisan hand crafted teflon (PTFE) combs made by yours truly!

Racks, Tube Holders

For objects like racks, tube holders, pipette hook dealies the 3D printer is ideal. You can custom design any type of rack you want to optimize your work flow. Since none of these objects are under heavy load or in harsh enviroments, they hold up really well! From left to right, we have a little tube rack with a magnet glued in, which I keep above my workbench. A funky orange test tube holder for drying stuff. Little baskets for the sink to hold little bits. A blatant ripoff of the Gilson pipette holder. All quite useful things, and you do save compared to buying from Fisher (20$ for a rack? Fisher y u do this).

Re-freezable Enzyme Storage Tray Thing

You know those tube racks with freezer jelly inside that you keep enzymes in to stop them warming up every time someone opens the freezer door? Yeah, those babies can run up to several hundred bucks each. Easy to make with a 3D printer, although you need to plan for the freeze expansion of the jelly (get it from old ice packs), otherwise you will have stuff oozing out like me. Otherwise it worked a treat, well worth making.

PCR tube centrifuge adapters

You want to spin down the droplets in your PCR tubes, but are wary since the last time you tried that you ended up with cracked tubes and your precious samples leaking everywhere? Never fear! Print out some adapters! Keep in mind, make sure these guys weigh the same as each other to avoid stressing your centrifuges.

GFP Light source for microscope

We wanted to be able to visualize GFP transfected mammalian cells, and found it inconvenient to carry our HIV infected cells to the nearest fluorescence microscope. We built a custom LED light source which was filtered and supplied to excite the GFP. The GFP emission was filtered through yet another…filter, which we built into the microscope, and into your eyes. Performance wasn’t nearly as good as the multi thousand dollar fluorescence scope, but for 200$ we were able to assess transfection efficiency, not bad. The attachment points to the microscope and to the light source were 3D printed.

There you go, a small taste of what you can make with a 3D printer in the lab. Cheap printers that are commonly available require time investment into assembly, tweaking and learning. I think it will be a while before 3D printers become widely accepted in our field, which I expect will happen as the learning curve decreases due to improving technology. If you have $20-30,000 to invest in a state of the art Stratasys printer, then it’s a bit of a different ballgame, but that 20 grand can also go into reagents, a new centrifuge or two, a transcriptome analysis…

Anyways, hope you enjoyed the read!