Genetic Research On The Cheap

When you think of DIY hardware, genetic research tools are not something that typically comes to mind. But [Stacey] and [Matt]’s OpenPCR project aims to enable anyone to do polymerase chain reaction (PCR) research on the cheap.

PCR is a process that multiplies a specific piece of DNA a few million times. It can be used for many purposes, including DNA cloning and DNA fingerprinting for forensics. PCR is also used for paternity testing.

The process involves baking the DNA at specific temperatures for the right amount of time. The DNA is first denatured, to split the helix into individual strands. Next, the temperature is lowered and primers are bound to the strands. Finally, another temperature is used to allow the polymerase to duplicate the DNA. This process is repeated to multiply the DNA.

The OpenPCR uses an Arduino to control a solid state relay. This relay provides power to two large resistors that act as heaters. A MAX31855 is used to read a thermocouple over SPI and provide feedback for the system. A computer fan is used to cool the device down.

A milled aluminium sample holder houses and heats the samples during cycling. The laser cut, t-slot construction case features some helix art, and houses all of the components. It will be interesting to see what applications this $85 PCR device can perform.

Via Adafruit

12 thoughts on “Genetic Research On The Cheap

  1. As a hacker, this is really cool. As a biologist, I’m worried about the precision of the heating and cooling cycles. Enzymes like to be at very precise temperatures for maximum efficiency, after all. Granted, if this can mimic the heating pattern for a replication cycle, more power to them.
    To add on, its also pretty easy to separate the cloned fragments using gel electrophoresis. I doubt that you need a chemical license for the components of that…the staining chemicals might be a different story, however, since most of them(such as Ethidium Bromide) are mutagenic.

  2. will this allow forensics grade dna work?

    my concern is me being a hobbyist scrap metal recycler rummage dumpsters for junk people throw out and if this will allow anyone to identify a person’s dna it could threaten dumpster rummaging because discarded comdomns and other porn toys could reveal their secrets and add another reason one may not like dumpster rummaging.

    1. 1) wut

      2) The PCR process only replicates DNA sequences to create long enough copies for further sequencing/testing. You would still need a sequencing process in order to get data that can be used to identify an individual.

      3) Even if you get the sequencing done, that sequence will be useless unless you have a database of sequences to compare against.

  3. @Inuyasha – think back to the old days of waterbaths. As long as you’re roughly in the region, you should be good. Perhaps less efficiency or a slower rate, but it should be negligible. If you’re worried, use an enzyme with error-correction. Also, some modern PCR machines don’t even use sensors for their peltier heating/cooling mechanisms. Rather, they are calibrated (temperature as a function of time and power input) and calculate the necessary cycles.

    @andy – primers are fairly cheap. It’s the enzyme (Taq and its derivatives) that’s gonna get you.

  4. Just to be clear – this is *NOT* an OpenPCR. OpenPCR is an entirely separate DIY PCR machine, originally funded on Kickstarter more than two years ago:

    The OpenPCR is available as a kit for $599, which is still only a fraction of what you would pay for an equivalent commercial machine – and it doesn’t require a metalshop like this version does.

  5. Uh, why don’t they use a £15 PID controller from ebay or something? It’s exactly the same thing, relay controlled, thermocouple-cum-relay driver. You can even buy a kit with the thermocouple and solid state relay for about £30

  6. Kudos on this hack! For a cheap PCR machine, new and ready to use check out

    It’s a cool new thermocycler. It is portable so you can share it easily. Hooks up to your phone or laptop.

    Full disclosure: I work with miniPCR. We support many biohackers, DIY bio, and science education projects.

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