How do you calculate the initial concentration of a sample? 2. Indicate whether you think that the number of cfu/ ml calculated would be too high or too low if you make this mistake. ~You add 9 ml of broth (water) to each tube. You add 1 ml of culture to the first tube and mix. You get distracted, and transfer 1ml of the dilutant (mixture of culture and broth) to the third tube instead of the second. You perform the rest of the series as described. High or LOW ?

How do you calculate the initial concentration of a sample? 2. Indicate whether you think that the number of cfu/ ml calculated would be too high or too low if you make this mistake. ~You add 9 ml of broth (water) to each tube. You add 1 ml of culture to the first tube and mix. You get distracted, and transfer 1ml of the dilutant (mixture of culture and broth) to the third tube instead of the second. You perform the rest of the series as described. High or LOW ?

Basic Clinical Laboratory Techniques 6E

6th Edition

ISBN:9781133893943

Author:ESTRIDGE

Publisher:ESTRIDGE

Chapter7: Basic Clinical Microbiology

Section7.6: Urine Culture And Colony Count

Problem 6RQ

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Indicate whether you think that the number of cfu/ ml calculated would be too high or too low if you make this mistake. 1.You intend to add 9ml of broth (water) to each tube and 1 ml of culture. Instead, you add 5 ml of broth to each tube and 5 ml of culture to the first tube. Then, you make a serial dilution of 1 ml into and from each tube as described. 2. You prepare 9 ml of broth (water) in each tube. You add 1ml of culture of every tube. 3.You add 9 ml of broth (water) to each tube. You add 1 ml of culture to the first tube and mix. You get distracted, and transfer 1ml of the dilutant (mixture of culture and broth) to the third tube instead of the second. You perform the rest of the series as described.
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The following are errors that people commonly make when they perform serial dilutions. Indicate whether you think that the number of cfu/ ml calculated would be too high or too low if you make this mistake. You intend to add 0.9 ml of diluent to each tube and 0.1 ml of culture. Instead, you add 0.5 ml of diluent to each tube and 0.1 ml of culture to the first tube. Then, you make a serial dilution of 0.1 ml into and from each tube as described. You prepare 0.9 ml of diluents in each tube. You add 0.1 ml of culture (from the overnight culture provided) to every tube. You add 0.9 ml of diluent to each tube. You add 0.1 ml of culture to the first tube and mix. You get distracted, and transfer 0.1 ml to the third tube instead of the second. You perform the rest of the series as described.
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