Another week zooms by! I’ve been working on sourcing for the aluminum heating block. One thing that’s a bit elusive is finding shops to prototype the block out of 1100 aluminum. Most prototype shops stick to 6061, which is a strong material, but we want as high conductivity and low specific heat as we can (reasonably) get, and 1100 is the purest alloy of aluminum.
The material itself is cheap but because it’s a softer (I think) grade of aluminum, it takes more time to machine. CNC machine time adds up very quickly so Josh and I are both putting out requests for quotes to different shops. Chime in if you have experience with this :)
I checked out the web traffic to our site, looks like a good handful of people are coming by looking for 2 weird things – “importance of the number of wells in a pcr machine” and “pcr how fast can aluminum be heated cooled”. Well, I wanted to answer both of these questions clearly:
1. Aluminum can be heated and cooled as fast as you can muster! Heating is certainly a lot easier, you just need to heat up. Cooling down is a little bit slower since you have to move the heat “somewhere else” in order to cool the block — like blow it out a side vent in OpenPCR. OpenPCR has a ramp speed of about 2 degrees C per second.
2. The number of wells in a PCR machine is an important point! I’ve used several PCR machines in the past, and all my work took up under 6 tubes (and each tube takes up one well). The minimum you should have when doing an experiment is 2 – a sample and a control, and usually you have more samples and several controls. OpenPCR right now as 16 wells — we thought about a lot of the recent projects people are working on, and they’re really a lot more social. 5 of us got together in a garage and looked at our SNPs, and that’s when we really started using up a bunch of wells. At the same time, having more wells makes the PCR machine’s design more complicated so we didn’t want to have wells that no one would ever use.
(Posting this retroactively)