Streak Plate Lab

What are things you could do wrong when prepping a streak plate?

1. Killing sample with heat by not letting loop cool

2. Don’t flame sterilize between each quadrant

3. Gouge the agar

4. Exposing plate to air contamination

5. Plate is stored upside down and condensation ruins the plate

6. Too many crossovers

What does the streak plate look like of you forget to flame sterilize between each quadrant?

A lawn

What does the streak plate look like if your loop is too hot?

No growth

What does the streak plate look like if there are too many crossovers?

The last quadrant looks as thick as the first

What does the streak plate look like of the agar is gauged?

Physical tears in the agar and uneven growth

Streak plate steps

1. Label plate

2. Sterilize loop

3. Sterilize tube

4. Collect sample

5. Sterilize tube

6. Streak zone 1 with loop

7. Sterilize loop

8. Turn plate

9. Grab microbes from zone 1 and streak them into zone 2

10. Sterilize loop

11. Grab microbes from zone 2 and steak them into zone 3

12. Sterilize loop

Streak plate goal

Isolate colonies

At least 15

Function of colonies from streak plate

Use to grow pure cultures

Use to study colony morphology