Stage transitions
By the end of this lesson
- Distinguish scheduled checks from advancement decisions
- Use observed readiness criteria
- Document why material advances or is held
See it
A stage transition should be based on biological readiness and the protocol's criteria, not only on elapsed time. Useful criteria may include shoot development, rooting status, morphology, contamination status, or other plant-specific observations.
Understand it
Distinguish scheduled checks from advancement decisions
Separate scheduled check dates from the decision to advance.
Advancement should be supported by the culture's condition and defined criteria, not elapsed time alone.
Use observed readiness criteria
Use objective observations where possible.
Time is a cue to examine the culture, while observations inform the actual stage decision.
Document why material advances or is held
Document why a culture was advanced, held, or discarded.
A due check can lead to holding rather than advancing material when biological readiness is absent.
Worked example
A check is due today, but the shoots have not met the protocol's next-stage criteria. Inspect and record their condition, then hold the culture with a reason. A reminder schedules attention; it does not establish readiness.
Explain your decision before opening the worked reasoning below.
Show the worked reasoning
A defensible stage decision connects observations to the criterion used.
Location and biological stage are separate concepts and should not be conflated in records.
Time is a cue to inspect, not always a command to advance.
Try it
What response fits the example?
Use the worked example above to explain your answer in your own words before taking the quiz.
Lesson quiz
Assessment version: 2026-10-15-v2. Previous reading-completion markers are retained. This revised quiz has its own result.
Apply it
Use the worked example to write a short decision record: what did you observe, which rule did you apply, and what would you check before acting?
Completion marks reading progress, not a quiz pass or professional certification.