Here's the dilemma. You've got 60 PCR reactions to run on a gel (3 sets of 20, excluding ladders), but the combs currently available in the lab only go up to 20 wells. That means no well (or wells) for a reference ladder (s)...argh. Plus, the teeth have gotten brittle with use and you have "20"-well combs with two or three gaps scattered across the comb...ARGH. Brand new combs cost £35 each...What? For a piece of plastic? Nope.

So we got them 3D-printed! After some research (Googling) we discovered that the Radcliffe Science Library has 3D printers, available to staff and students of Oxford University. If you're affiliated with the University, definitely have a look at their website. They run regular '3D Printer Bring a Design/Object" events to get people acquainted with 3D-printing, or you can contact them directly to discuss projects/designs etc.

Anyway, the prototypes were completed and we gleefully brought them back to the lab for testing. And eeek...some measurements were off (Vanessa says: Sorry, my fault. I found the errors in the initial sketch. Oops). As you can see, the comb doesn't fit into its slot...

Not to be outdone though. After some manual adjustments (poor blade)...

...and with the help of some modelling clay props to correct the depth...they finally fit! Next question is, will PLA hold up in hot melted agarose, considering its low glass transition temperature of 60-65 degrees Celsius?

Shown here with hot melted agarose poured in. Happy to report that while the combs became 'pliable', they managed to hold their shape well enough as the gel cools and sets.

Ta-da! Running samples in 21 lanes, all in a row with no gaps and perfectly aligned. :)