Home Cell Biology Design and Use of Multiplexed Chemostat Arrays
Cell Biology JoVE (Open Access) Citable · DOI

Design and Use of Multiplexed Chemostat Arrays

DOI: 10.3791/50262-v
What you'll learn
  • Build and assemble a miniature chemostat array from readily available parts
  • Set up and operate multiplexed chemostat systems for continuous culture experiments
  • Perform time-zero sampling and daily measurements in chemostat experiments
  • Conduct experimental evolution and functional genomics screening using ministats
Protocol

Biopharma Insights We developed and validated a small-footprint array of miniature chemostats built from readily available parts for low cost. Physiological and experimental evolution results were similar to larger volume chemostats. The ministat array provides a compact, inexpensive, and accessible platform for traditional chemostat experiments, functional genomics, and chemical screening applications.

Difficulty
intermediate
Total time
~2–3 weeks (continuous culture experiment); ~1–2 days setup and teardown per experiment

Steps

1
Understand ministat design and operating principles

Learn the fundamental design of miniature chemostats and how they maintain continuous culture conditions. Understand how the ministat array provides a compact platform for traditional chemostat experiments.

▶ 01:18
2
Review ministat array anatomy and components

Identify and understand the physical structure and key components of the ministat array system. Familiarize yourself with the layout and functional organization of the apparatus.

▶ 02:03
3
Clean and assemble ministat array components

Perform initial cleaning and basic assembly of ministat array parts before experimental setup. Prepare components for sterile handling and culture inoculation.

▶ 03:11
4
Mark culture tubes at working culture volume

Mark the desired working culture volume on culture tubes to maintain consistent culture density across the ministat array. This ensures reproducibility across parallel experiments.

▶ 03:40
5
Construct cork assembly for culture chambers

Assemble cork or closure structures that seal culture chambers while allowing gas exchange and tubing connections. Ensure airtight seals for proper chemostat operation.

▶ 04:11
6
Set up gas washing bottle for air hydration

Configure a gas washing bottle to humidify incoming air and prevent culture evaporation during continuous operation. This maintains stable culture volume throughout the experiment.

▶ 05:48
7
Configure 4-port manifold for air flow division

Assemble and calibrate a 4-port manifold to evenly divide air flow among multiple ministat chambers. Ensure balanced aeration across all parallel cultures.

▶ 06:39
8
Set peristaltic pump and heating block parameters

Configure the peristaltic pump for media flow rate and set heating block temperature to maintain culture at physiological conditions. Validate settings before running experiments.

▶ 07:35
9
Assemble air tubing connections

Connect air inlet tubing from the manifold to each ministat chamber, ensuring secure connections and no leaks. Verify proper gas flow through each chamber.

▶ 08:24
10
Assemble effluent tube assembly

Set up outlet tubing to collect spent culture medium and cells from each ministat chamber. Ensure sterile collection without backflow contamination.

▶ 08:50
11
Assemble media tubing from supply carboy

Connect tubing from the media carboy through the peristaltic pump to each ministat chamber. Ensure proper tubing sizing and tight connections to prevent leaks.

▶ 09:08
12
Prepare effluent sampling containers for collection

Set up sterile or disinfected containers to collect effluent from each ministat during the experiment. Label containers and position collection tubes appropriately.

▶ 10:21
13
Autoclave assembled parts and culture chambers

Sterilize fully assembled ministat array components and culture tubes using standard autoclave protocols. Ensure all tubing and connections withstand sterilization.

▶ 11:01
14
Connect all tubes to the culture chamber

After autoclaving and cooling, aseptically connect media inlet, air inlet, and effluent outlet tubes to each culture chamber. Verify all connections are secure and sterile.

▶ 11:34
15
Prepare and autoclave media carboy

Fill the media carboy with sterile growth medium and autoclave to eliminate contaminants. Ensure proper filling and sealing before sterilization.

▶ 12:33
16
Inoculate ministats and initiate continuous culture

Aseptically inoculate each ministat chamber with starter culture and begin continuous operation with media flow and aeration. Monitor initial growth and stabilization.

▶ 12:55
17
Perform time-zero sampling of cultures

Collect initial samples from each ministat at the start of the experiment for baseline measurements. Record optical density, viable counts, or other relevant parameters.

▶ 15:13
18
Conduct daily measurements and monitoring

Perform routine daily measurements of culture parameters such as optical density, growth rate, and pH. Monitor system stability and troubleshoot any operational issues.

▶ 16:08
19
Terminate experiment and clean up apparatus

Shut down the chemostat system, collect final samples, and disassemble the ministat array. Clean all components thoroughly and decontaminate according to biosafety protocols.

▶ 16:52
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