Duane Storey@DuaneStorey
I have three PCBs/products on the go right now.
1) The first is the fluorometer, a device that uses light to measure RNA/DNA concentration. That let's me actually understand how much RNA/DNA I have after extracting it, which lets me start doing things like reverse transcription and PCR etc.
2) I need a agarose gel setup for electrophoresis. I already built a tray but I also need a power supply (I can use my bench supply at home for now), and also a transimmuninator - basically I need to shine light through the gel at a specific wavelength, in this case 470nm (blue) which then causes the DNA/RNA in the gel to emit another color, green. Using a visual amber filter, you can then view the RNA/DNA in the same and approximately what size each of the bands are, and even take a photo of it with an iPhone etc and get a rough spectral shape with it. This goes hand in hand with #1 as often you take the result of the extraction, measure concentration, then run the gel to see what it looks like (i.e. RNA should show two strong peaks, 18S and 28S). What's cool is later if you do PCR amplification, you can run the gel and see where everything is bundled up on the gel (a dark solid band). I it matches the size you think for your amplicon, you can simply physically cut the gel out, clean it using a kit, and now you've isolated that DNA simply by physical means.
3) I then need to finish the thermocycler, which I'm about 50% done already. This is the device that will raise and lower the temperature on a group of samples with one cycle every 60 to 90 seconds. At the higher temperature, the two strands of DNA come apart into individual strands. When you lower it to the lower temperature, the PCR primers that you added bind to the proper locations, and the DNA polymerase completes the entire second strand. So in one cycle, you went from 1 complete double stranded DNA, to two incomplete single stranded ones, to 2 complete double stranded ones. Next cycle the same thing happens, but now you have two breaking apart, and four coming out the bottom. Each cycle is roughly an exponential (x2) increase in material.
I need all three together to do everything I want in August, so I'm frantically trying to finish them all. I also wouldn't mind releasing a few of these when I know they work etc and are safe, even as DIY kits, as I started my career as a manufacturing engineer and I've been itching to make a physical product since before covid. And this scratches a real item for me and I suspect other people, as evidenced by the massive attention people have gotten sequencing their dogs or even their own DNA at home etc.
I realized the optics inside the transilluminator for the gel aren't much different than what ELISA tests need for detection, so I am baking three optical channels into it. In theory, with the right enclosure, you could visualize agarose gel and also image an ELISA 96 well plate.
Still very rough at this point, but I have the rough arrays laid out for the high power 470nm blue LEDs (gel), and the 450nm + 650nm arrays for the ELISA. These will project onto a diffuser that you can slide the gel system onto or an ELISA plate. First prototype I'll probably use my iPhone to take the photos of the ELISA, but there is no reason I can't embed a camera in it in v2. But baby steps, ELISA is the least of my worries at this point. But I always try to future proof my boards simply because it's a lot of work getting them made an also hand assembling these myself (which I do) is time consuming.
The only components I struggle with still are USB-C. I blew out the USB-C port in Macbook Air a few years ago due to a bad solder connection I did on my own board. So I may pay them to just do those ones. But typically the rest I can do slowly with my HD USB microscope.
