Locate the task in the fluid path first
Arrows indicate task relationships, not that every component is connected in series in one tube. Check valve positions, pump wetted boundaries and operating states for each branch.
Mark the feed source, experimental vessel, sample receiver and discard path separately. Include sampling-line renewal and drainage in the withdrawn volume, so a small analytical sample is not mistaken for the entire disturbance to the experiment. Select wetted materials and the cleaning or sterilization procedure for the complete path that contacts the culture or collected sample.
Common product roles and application guides
| Product category | Role in this instrument |
|---|---|
| Syringe pump | Metering individual feeds and samples |
| Valveless metering pumps | Suitable repeated and continuous feeding |
| Fluidic valves | Routing for feeding, sampling and maintenance; tubing shutoff and replacement |
| Bubble and pressure detection | Signals for controller event logging in process records |
| Tubing and fittings | Connect process vessels and liquid branches |
Operating requirements differ by step
| Stage | Task category | Operating conditions to define |
|---|---|---|
| Feeding: define the purpose and delivery mode | Experimental additions | Medium, inducer or adjustment liquid; intended addition time and delivered volume; vessel volume; mixing or equilibration required before the next experimental observation |
| Online sampling: balance representativeness and volume disturbance | Repeated collection of an interpretable sample | Target cells, particles or dissolved analyte; sampling position and interval; path-renewal discard; receiving volume; permitted pretreatment and handling before analysis |
| Drainage and maintenance: recheck contamination boundaries after restart | Preparation for the next experimental operation | Whether culture, collected sample or waste contacts the serviced path; cleaning-liquid destination; actual inlet condition for drainage; sealing, priming and contamination checks before reuse |
Feeding: define the purpose and delivery mode
For medium, inducer or adjustment-liquid additions, specify why the experiment needs the addition and when the resulting sample will be assessed. Select a drive for the actual dose or delivery pattern, then verify liquid received by the vessel. Record the addition with the experimental time point; correct delivered volume does not by itself establish adequate mixing or the intended biological response.
Online sampling: balance representativeness and volume disturbance
Choose the sampling point and handling sequence for what the assay must measure: cells or particles may need to remain in the sample, while another method may require a separated liquid fraction. Refresh stagnant liquid before collection as required by the sampling method, and include that discard in the experimental volume budget. Compare collected samples with the source where practical to assess settling, adsorption or old-sample mixing.
Drainage and maintenance: recheck contamination boundaries after restart
Keep cleaning liquid and discarded samples out of the culture and product-receiving paths. Select supply, liquid drainage or gas-containing aspiration according to the actual incoming medium, including cells, biomass or foam where present.
After servicing a connection or replacing a component, recheck assembly, sealing and priming. Establish whether the interruption or maintenance changed the next sample, its collection time or the contamination-control boundary before using it to interpret the experiment.
Explore configurations through product application guides
Validate the complete cycle through application results
Record actual additions, collected samples and discarded volumes alongside the experimental time points. Evaluate delivery separately from the biological or analytical result so that a changed outcome can be traced to the liquid operation, sampling method or experiment itself.
| Step to validate | Measurements or observations | Priority troubleshooting checks |
|---|---|---|
| Feeding: define the purpose and delivery mode | Measure the volume received for the intended addition pattern and record its timing; evaluate mixing and the subsequent experimental response separately. | Check the actual source, residual liquid, incomplete delivery and timing before attributing a changed result to the formulation or biological response. |
| Online sampling: balance representativeness and volume disturbance | Record collected and discarded volumes; compare the intended target fraction in the collected sample with the source using the experimental method. | Investigate old-sample mixing, settling, adsorption and unintended loss of cells or analyte during pretreatment. |
| Drainage and maintenance: recheck contamination boundaries after restart | Check sealing, priming, residual cleaning liquid and the next collected sample after servicing, using the contamination checks required by the experiment. | A restored pump action does not show that the sample is unchanged; review maintenance contact, changed collection timing and any uncertain sample history. |
A repeatable dose establishes one part of the experimental operation. Sample representativeness, mixing and contamination control need checks appropriate to the culture or reaction method.
Common selection and recovery questions
Must sampling discard be included in the experimental volume record?
Include the collected sample, path-renewal discard and other withdrawals. Compare the total with the culture or reaction volume and the experiment's sampling plan, then check that the received fraction represents the intended target.
Can the next experimental sample be accepted immediately after maintenance?
First verify assembly, sealing, priming and the contamination-control boundary. Record any changed sample timing or uncertain liquid history before interpreting the next result. See the synthetic biology guides for extended-run control and interruption handling.