Presumptive Test- Lab 41 Flashcards Preview

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Flashcards in Presumptive Test- Lab 41 Deck (4)
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1

List the three steps of water testing in order

1. Presumptive test
2. Confirmed test
3. Completed test

2

What constitutes a positive presumptive test

Production of acid is determined by the change of the medium from green to yellow.
Production of gas you look for a gas bubble in the durham tube

3

What do yellow and blue tubes with no bubbles indicate

Negative

4

Define coliforms

All facultative anaerobic gram-negative rods which produce acid & gas from lactose fermentation in 48 hours and 35°C