Science Enhanced S&S Biology - Virginia Department of ...

10. Return to the classroom. Back in the classroom after sampling: 11. Record initials, date, and locations of samplings on Petrifilmâ„¢ plates. 12. Shake a stoppered test tube containing one sample 25 times. 13. Remove the stopper from the tube. 14. With pipette, withdraw 1 mL of the water from test tube. 15. ................
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