Comment on Prove your humanity.

• beeng@discuss.tchncs.de ⁨1⁩ ⁨day⁩ ago

  Nice username

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  • Sterile_Technique@lemmy.world ⁨1⁩ ⁨day⁩ ago

    Image

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• icelimit@lemmy.ml ⁨1⁩ ⁨day⁩ ago

  1 through to the end are all made with new, sterile… sticks?

  Look ma, I’m a biochemist now!

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  • Sterile_Technique@lemmy.world ⁨1⁩ ⁨day⁩ ago

    Pretty much. It’s like a little wire loop - sterilize it with a bunsen burner, let it cool, then take a swab from your source specimen and drag it into your agar for that section 1. Sterilize it again with the burner, cool, then drag through the last couple lines of 1 to get region 2. Repeat for 3 and again for 4. The sample size of individual microbes gets exponentially fewer each time - done correctly and region 4 is dotted with individual cells, which you leave alone for a while to incubate, then come back and start making your observations like how it’s interacting with the agar, what color, texture etc; smear it onto a microscope slide, see how it responds to different stains, it’s shape, it’s arrangement… then start checking all those findings against known properties of different microbes until you find a match.

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    • BrowseMan@sh.itjust.works ⁨4⁩ ⁨hours⁩ ago

      Another way is one use throwable plastic hoop. Which is completely stupid, but well…

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    • janus2@lemmy.zip ⁨6⁩ ⁨hours⁩ ago

      raise your hand if you ever wrecked a plate by forgetting to cool the loop

      ✋🫩

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      • Sterile_Technique@lemmy.world ⁨6⁩ ⁨hours⁩ ago

        I made that mistake several times, but iirc it was always a recoverable error. When I stuck that hot loop into the agar it would sizzle, which would tell me I just murdered every bacterium that loop touched; so resterilize actually allow it to cool this time, and repeat the botched step in a slightly different location to pass through a section of bacteria that I hadn’t just dropped a nuke on.

        …which is probably shitty technique, but it got me good enough results to get good enough data for class.

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