Tissue culture concepts
Contamination tracking basics
Contamination is one of the most common causes of culture loss in tissue culture. Recording every contamination event helps identify recurring patterns, improve laboratory practices, and preserve a complete history for every culture.
Why track it at all
Spot patterns before they spread
One contamination event may be an isolated incident. Multiple events affecting the same room, protocol, or media recipe often indicate a pattern worth investigating.
Understand contamination trends
Logged contamination records help reveal recurring problems and measure the impact of contamination over time.
Guide recovery decisions
Recording contamination outcomes helps identify which recovery approaches are most effective and when cultures can be successfully recovered.
Common contamination indicators
Many contamination events begin with subtle changes rather than obvious signs. The examples below are common observations in tissue culture, but they are not definitive diagnoses. Always record what you observe rather than assuming the cause.
| Observation | Possible cause |
|---|---|
| Cloudy or turbid medium | Possible bacterial contamination |
| White, grey, or coloured fuzzy growth | Possible fungal contamination |
| Rapid media discoloration | Possible contamination or media degradation |
| Unusual odour when opening a vessel | Possible bacterial contamination |
| Tissue browning or blackening | Oxidation, stress, or possible contamination |
| Excessive callus decline or tissue collapse | Possible contamination or physiological disorder |
How to log a contamination event
Open the affected plant or explant and add a contamination log. If contamination is discovered during a transfer, it can also be recorded directly from the transfer.
| Field | What to record |
|---|---|
| Type | Bacterial, fungal, viral, physiological disorder, pest, unknown, or other |
| Severity | Mild observation, moderate concern, or severe loss |
| Observed on | Date and time the contamination was noticed |
| Description | What you saw: colour, location within the vessel, spread pattern, smell |
| Follow-up action | What was done — discard, move to Quarantine, treat, photograph, monitor |
| Outcome | Final result: Recovered, partially lost, discarded, or still under observation |
| Resolved | Mark the event closed once the outcome is known |
After you log it
If the culture requires isolation, move the explant to the Quarantine stage while monitoring its recovery. If the culture cannot be recovered, move it to Discarded, record the final outcome, and close the contamination log.
Use comments to document follow-up discussions, mention teammates, and record decisions related to the contamination event.
Best practices
- Log contamination the same day you observe it. Memory degrades fast and timestamps matter.
- Record even minor observations. A 'suspected contamination' that clears up still tells you something about that vessel's history.
- Use the description field freely — detail about appearance, location, and spread is the hardest thing to reconstruct later.
- Always mark the outcome when you discard or recover culture. An open log with no outcome makes future analysis less reliable.
- Review contamination logs by room, media recipe, or protocol to identify recurring patterns.