5 ms·

If microplastics are everywhere in flesh/brains/etc., how do you construct a blank without them? Isn't that the very issue here?

margalabargala 7mo ago
Exactly. If you run a blank and it has no fewer microplastics than the thing you are studying, then that tells you something.
- timr 7mo ago
  Well, in this case, it tells you that you may have contaminated the sample with your lab setup.
fercircularbuf 7mo ago
I don't believe the point is to construct a blank without them. Rather, the point is to capture what is already there (contaminants) so you can calibrate during the real sample.
thephyber 7mo ago
The point isn’t to have 0 microplastics according to the test. The point of the blank is to identify the base level given the current testing environment. Then you test again with the variable. If the majority of the microplastics contaminants were introduced in the blank, the variable would show minimal, if any, bump.
godelski 7mo ago
Here's a very naïve example to help illustrate how you can do a "blank" (a control). Say you're testing a sample of water in a test tube. Repeat all steps in exactly the same way, but use distilled water. You can even do all the steps and use no water! (Including having an empty container and pouring nothing from the empty container into the test tube). By doing things like this you create samples that allow you to look for contamination. How do you know that the thing you're testing has microplastics? (Or whatever) because it has more than the blanks/controls. That's it. Congrats, you've isolated a variable in your experiment. Btw, this is pretty common practice. In fact! Here's a video of someone doing exactly that "nothing" control looking for microplastics. Those steps are done at 10:20. https://youtube.com/watch?v=oDDQjEpuFfQ https://youtube.com/watch?v=oDDQjEpuFfQ
- vel0city 7mo ago
  > Repeat all steps in exactly the same way, but use distilled water. But how do you know your source of distilled water isn't also contaminated?
  - godelski 7mo ago
    You continue reading the comment and use the other version of a blank
    - vel0city 7mo ago
      So why even bother mentioning the distilled water? And if you're testing an aqueous process don't you pretty much need some fluid to put through the process?
      - godelski 7mo ago
        I gave the second example to try to avoid this type of response. It's not that hard to grasp. You don't need some fluid
        vel0city 7mo ago
        So then maybe don't give the first if you know its a flawed example? Its not that hard to grasp. > You don't need some fluid Entirely depends on your testing procedure, and not something always true. Like in the video you posted he pretty much needs to have some kind of fluid through the process. Otherwise, he'd be missing out on contamination in the process of artificial mastication, running through the filtration process, etc. Sure, examine a dry and plain filter as well to see what the filters look like and ensure they're not just completely covered in particles as well, but you're then missing out testing quite a lot of the rest of the process.
        godelski 7mo ago
        > So then maybe don't give the first if you know its a flawed example? It's not a flawed example. As you can understand from the other poster talking about baselines. > Its not that hard to grasp. I agree! > Like in the video you posted he pretty much needs to have some kind of fluid through the process. And it looks like you're understanding too! But if he used a different process he could have used it dry. There's a lot of ways to skin a cat. Different ways create different constraints. So I'm confused here, did you just want to argue or did you actually want to understand? Because at this point it seems like you understand. And frankly, I don't want to argue
SarahC_ 7mo ago
That's EXACTLY what the blanks for! It lets you see what to expect with "All things being the same - just not with the sample in place." You sure you're a coder?
- bn-usd-mistake 7mo ago
  > Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

margalabargala 7mo ago

Exactly. If you run a blank and it has no fewer microplastics than the thing you are studying, then that tells you something.

timr 7mo ago
Well, in this case, it tells you that you may have contaminated the sample with your lab setup.

fercircularbuf 7mo ago

I don't believe the point is to construct a blank without them. Rather, the point is to capture what is already there (contaminants) so you can calibrate during the real sample.

thephyber 7mo ago

The point isn’t to have 0 microplastics according to the test. The point of the blank is to identify the base level given the current testing environment. Then you test again with the variable. If the majority of the microplastics contaminants were introduced in the blank, the variable would show minimal, if any, bump.

godelski 7mo ago

Here's a very naïve example to help illustrate how you can do a "blank" (a control). Say you're testing a sample of water in a test tube. Repeat all steps in exactly the same way, but use distilled water. You can even do all the steps and use no water! (Including having an empty container and pouring nothing from the empty container into the test tube). By doing things like this you create samples that allow you to look for contamination. How do you know that the thing you're testing has microplastics? (Or whatever) because it has more than the blanks/controls. That's it. Congrats, you've isolated a variable in your experiment. Btw, this is pretty common practice. In fact! Here's a video of someone doing exactly that "nothing" control looking for microplastics. Those steps are done at 10:20. https://youtube.com/watch?v=oDDQjEpuFfQ https://youtube.com/watch?v=oDDQjEpuFfQ

vel0city 7mo ago
> Repeat all steps in exactly the same way, but use distilled water. But how do you know your source of distilled water isn't also contaminated?
- godelski 7mo ago
  You continue reading the comment and use the other version of a blank
  - vel0city 7mo ago
    So why even bother mentioning the distilled water? And if you're testing an aqueous process don't you pretty much need some fluid to put through the process?
    - godelski 7mo ago
      I gave the second example to try to avoid this type of response. It's not that hard to grasp. You don't need some fluid
      - vel0city 7mo ago
        So then maybe don't give the first if you know its a flawed example? Its not that hard to grasp. > You don't need some fluid Entirely depends on your testing procedure, and not something always true. Like in the video you posted he pretty much needs to have some kind of fluid through the process. Otherwise, he'd be missing out on contamination in the process of artificial mastication, running through the filtration process, etc. Sure, examine a dry and plain filter as well to see what the filters look like and ensure they're not just completely covered in particles as well, but you're then missing out testing quite a lot of the rest of the process.
        godelski 7mo ago
        > So then maybe don't give the first if you know its a flawed example? It's not a flawed example. As you can understand from the other poster talking about baselines. > Its not that hard to grasp. I agree! > Like in the video you posted he pretty much needs to have some kind of fluid through the process. And it looks like you're understanding too! But if he used a different process he could have used it dry. There's a lot of ways to skin a cat. Different ways create different constraints. So I'm confused here, did you just want to argue or did you actually want to understand? Because at this point it seems like you understand. And frankly, I don't want to argue

SarahC_ 7mo ago

That's EXACTLY what the blanks for! It lets you see what to expect with "All things being the same - just not with the sample in place." You sure you're a coder?

bn-usd-mistake 7mo ago
> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html