The lid and gas input/output

[jbe]

I’m interested in whether an inlet on the lid can be used for continuous gas sparging (e.g. to supply CO2 at an elevated concentration). Is the gas composition in the reactor normally determined by air in the media inlet/outlet lines, or is the lid sufficiently non-airtight to allow some gas exchange?

• This topic was modified 5 years, 3 months ago by jbe.

[harrison]

Hi Jbe!
The standard lid is open to atmosphere, so you wouldn’t be able to regulate the gas inside. However, the device uses standard test-tubes with threaded 22-400 closure, so you should be able to find some commercially available lid (or make your own) that fits those tubes and allows you to make a gas-tight seal on the tube.
Making a custom air-tight lid is something we are currently considering, but we would likely wait a while until we can have a big demand before ordering them in a large quantity… thoughts?

[harrison]

I am just getting back to this topic, since we have now designed a custom lid which would solve this issue, take a look at the hardware page: https://chi.bio/hardware/

[afabregas]

Hi both!

The 3D printable airtight screw top lid is a very nice upgrade indeed! Would be really interested in giving it a try.

I tried to download the ‘Chi.Bio screw-top lid (20mL, 3 port) V1.1’ STL file from the hardware page but it seems the link is currently not working.

[harrison]

Not sure why that wasn’t working; I have just updated the page so that the link should now correctly download a .zip containing a .stl.
If you make a different version via modification or other changes I’d be happy to put it up there as well, I’m sure people would find it helpful!

[jbe]

Cool! Sorry I didn’t get back to your original reply. I’m preparing to shift labs at the moment but hope that I’ll have a chance to revisit this seriously once I’m up and running, presumably mid-2020

[aliceboo]

Hello Harrison,

We were wondering if it would be much trouble to add a skirt to the gas lid. We’re finding that there is quite a bit of light leaking through from the sides and wondered what effect this has on the measurements. We were also investigating how to sample from the chamber using a robot but the holes are quite small, and it’s quite challenging to have an accurate aim. Do you know if it would be possible to make a slightly bigger hole at the top for the sampling?

[harrison]

As to the skirt; yes this could easily be added. Would just have to think about dimensions etc. However, first it might be good to test if the light getting into the chamber is actually a problem. This could be done by turning the lights on, putting some cells in, and then taking a spectrometer measurement at x512. If the readings are all close to zero (<50 or there abouts), then I'd say it is likely that the light leakage is not too significant.

If you look at the current version of the lid on the hardware page it has arms and an internal barrier to prevent any moisture escaping, this may help with getting it perfectly positioned each time for sampling.

We can easily make the holes in the top bigger (or add more holes) if that is what you need. Do you have any kind of 3D modelling software (there are some free packages!) available? If so I can export the model in any format that works for you so that you can edit it to suit your exact needs.

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