[GabiM]

Hi Harrison,

Just wanted to let you know that I’ve managed to get it working. I’m really sorry to have bothered you with so many questions. This is the first time Chi.bio has been used in our department, and understanding it, particularly the code changes necessary to adapt to our aim, has been quite difficult.

Thanks again for your patience and assistance

[GabiM]

Hi Harrison.

So I tried to reproduce the experiment, but I’ve failed again 🙁

Here’s what I did: set target OD to 0,4 in UI and in the app.py, line 64, I changed the parameter “zig” with 0,1. So that, I imagined my OD shoul have fluctuated between 0,3 and 0,5. Instead, what I got was a graph with OD fluctuating between 0,38 and 0,44. Also, the growth rate was not calculated (the “growth_rate” column of the csv output file is 0).

What else I have to do to make this work? Can you please give me a detailed explanation?

Thanks in advance,
Gabriella

• This reply was modified 4 days, 2 hours ago by GabiM.
• This reply was modified 4 days, 2 hours ago by GabiM.

[GabiM]

Hi Harrison.

Thanks for the tip. I’ll try to do that.

[GabiM]

Hi!

Because I need a slower dilution rate. I get approximately 14 mL per hour and I need 5 mL per hour. Since I’m using the slowest pump rate (0.001), I thought I needed to increase the period of the pump.

I did change the cycle to 10 minutes, but it didn’t work. I’ve notice that if I increase the cycle time, the volume added to the tube is higher too. So it does not get smaller.

[GabiM]

Hi Harrison.

Thanks for the replies!

Regarding reply #1900, your explanation was very helpful and confirmed what I observed yesterday testing this. Initially, I was envisioning a continuous inflow and outflow of media, similar to our lab’s peristaltic pump-based chemostat and that’s why I may have understand it wrong.

For reply #1902, thank you for the suggestions. I will try the tape solution first. If that proves ineffective, I will explore the valve option, although importing items to Brazil can be challenging.
I am also considering adjusting the pump period through code modification. As a programming beginner, I believe the following steps are necessary:
1) conect the putty
2) set de date and hour
3) move to chi bio folder (cd chibio)
4) confirm that the app.py file that contains the code is in that folder with ls command
5) open this file with an text editor (nano app.py)
6) in the PumpModulation function, go to the line #789 and change the value from 1.05 to 10.05 (or whatever time i want to)
7) save the file (crtl + 0 in nano)
8) run the command bash cb.sh to start using it

1) Connect via PuTTY.
2) Set the date and time.
3) Navigate to the Chi.bio directory (cd chibio).
4) Verify the presence of app.py using ls.
5) Open app.py with nano (text editor).
6) In the PumpModulation function, change the value on line 789 from 1.05 to 10.05 (or the desired value).
7) Save the file (Ctrl+O in nano).
8) Execute bash cb.sh to restart the application.

Please let me know if these steps are correct or if you have any recommendations.

Thanks again,
Gabriella

[GabiM]

Hi Harrison.

I managed to get the pumps working. Now I understand a little better how it works. All the questions above about how to turn it on and the fact that the pumps works periodically are settled now.

I’m advancing slowly and now I’ve got new issues. Te first one is how I can make the pumps run continuously? I’ve been testing the pump rates to find the best dilution rate for my experiment. I wat to achieve 10 ml per hour, considering a 10 mL culture in the tube that goes into the reactor. So far, it seems that I will have to use a very small rate and I noticed that after a while, the medium is no longer added to the tube in the reactor. It seems that the pump does not have strenght enough to push the small volume into the tube. This happend with a 0.01 rate. What can I do to solve this?

Earlier, you mentioned that the outflow pump shold have a rate higher than the inflow rate. How much higher is enough? 2 times, 5 times, 10 times?

[GabiM]

I’m not sure I know how to do that. Here’s what I’m thinking. Please let me know if it’s correct.
The turbidostat mode is not the dafault. To activate it I have to click on “switch” in the OD regulation section and then the OD will be maintained at a certain value os my choice, right? Why you don’t recomend it?
For activation of the pumps, shoud I just set a new rate and then it will immediately work?

[GabiM]

Just an update: I was able to make it work. It was indeed a cable problem. But I could only solve it when I changed the cable. The one that was purchased with the devide does not work at all.

[GabiM]

Hello, Harrison.
Unfortunately it doesn’t work. Anything else I can do?

[Author]

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