Applied Biosystems 373 DNA Sequencer Teardown

[@msylvain59]

Thanks for this awesome and informative teardown, it is not the kind of stuff you can expect to pick up from the roadside while it's garbage day...

[@weldmaster80]

I recently got a 377, this was A BIG help thanks!

[@douro20]

These machines were designed for the rapid analysis of DNA extracted from a test subject. It uses a modified form of gel electrophoresis known as laser fluorescence chromatography. The gel to be used is loaded similarly to a regular electrophoresis gel, with the exception of the dye used, which is actually a mixture of dyes which are formulated to attach to specific base pairs. The gel cassette is then loaded into the machine, which applies about 100v across the gel at a very specific...

[@douro20]

The dyes, which have broken down the DNA into single strands and attached themselves to specific base pairs, fluoresce at different frequencies depending on the nucleotides present at that specific location. These patterns of fluorescence are the actual DNA sequence which is recorded.

[@mikeselectricstuff]

Multi-line lasers are AWESOME!

[@Aussie50]

wow thats some cool kit!, never seen one of those before!. Is the laser beam visible to the naked eye, or just the camera? I have never had the pleasure of working with such a large laser.

[@douro20]

...current. As in standard gel electrophoresis, heavier molecular strands are carried by the current more slowly than smaller ones, effectively separating the DNA strands which were earlier broken down in solution. After the gel is run, the machine analyzes the results using laser fluorescence with an argon-ion laser.

[@ChumpusRex]

Hard drive sounds quite healthy to me. That's just the old style ball-bearing drive. They made a heck of a noise. We still have one at work in an external drive. It's louder than the HVAC.

[@008626]

yeah it's visible, it lases in the green-blue-violet areas of the spectrum although the camera doesn't show the violets very well

[@008626]

Hard to say accurately, the beam itself is just the temperature of the room. Heat from a laser beam is the result of the light being absorbed by the surface it is hitting, the beam itself is not actually hot. If the beam was focused tightly on a piece of dark colored paper you may see temperatures of around 400 degrees F. Think of it like a black car in the summer. The car gets hot from being in the sun, but the air which the sunlight travels through is not directly hot (relatively).

[@008626]

the old quantum fireball is struggling to read data, it tends to hand and take many minutes to boot sometimes, it's probably on the verge of failure, you're right about the bearing noise though which is normal but it re-initialized several times (couldn't really hear it on the video)

[@jazzmessenger8]

Does this machine use capillary electrophoresis? I did not see any capillary tubes.

[@helicoptered]

The beam focus point

[@008626]

what part of the laser?

[@douro20]

This machine would probably still be in use if higher performance sequencers didn't exist...

[@helicoptered]

what is the temperature of this laser?

[@008626]

correct

[@douro20]

Looks like you got a fingerprint on the diffraction grating...

[@008626]

it's just dirty, it's a cheap $0.50 plastic one that i keep in my portable laser case, plus the argon laser itself has a dirty light sensor which is causing a lot of spatter

[@LPFthings]

Bah, I want a first click firing argon! :P

[@cstgwu1]

chek the fuses

[@cstgwu1]

get the laser to burn some thing see what you can make it do that would be cool