Culturing and colony data lab
Tue, Oct 13, 2026 · Week 8 · Genetics of Disease (Medical Interventions)
Today's goal: Streak and incubate a culture, then count and describe colonies to gather data on bacterial growth.
What a finished product looks like
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
I streaked my plate using aseptic technique, labeled it with my initials, the date, and 'Sample 1,' and incubated it. After growth, I counted and described the colonies.
Target colonies: I counted 14 colonies that all looked the same, which suggests a pure culture descended from one strain. Each was small (about 1 mm), cream colored, round, and had a smooth edge.
Contamination: I found 2 colonies that looked different (larger, yellow, fuzzy edges). I did not count these as target colonies because they are a different organism. I recorded them separately so my analysis stays clean.
Conclusion note: Because almost all my colonies share one morphology, I am confident most of the plate is my target strain.
| Group | Count | Size | Color | Shape | Edge |
|---|---|---|---|---|---|
| Target | 14 | ~1 mm | cream | round | smooth |
| Contamination | 2 | ~3 mm | yellow | irregular | fuzzy |
Also due today: Photograph your plate and table and bring them to the mutation and HGT analysis.
WebXam problem for today's skill
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.