Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10^-5dilution of phage was added to bacterial culture.What is the initial concentration of the undiluted phage? A)6.7 × 10^-5pfu/ml B)0.1 × 10⁵pfu/ml C)6.7 × 10⁵pfu/ml D)67 pfu/ml E)6.7 × 10⁷pfu/ml pfu = plaque- forming units

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Quizplus · Accepted Answer

To calculate the initial concentration of the undiluted phage, you use the formula: (Number of plaques × dilution factor) / volume plated. Given 67 plaques on a plate with 0.1 ml of a 10^-5 dilution, the calculation is (67 × 10^5) / 0.1 = 6.7 × 10^7 pfu/ml.

Assume That One Counted 67 Plaques on a Bacterial Plate