Five grams of soil were added to 45 ml of sterile water and shaken vigorously. After that, 0.1 ml of this was added to 9.9 ml of sterile water. This was further diluted by four successive 1/10 dilutions. The last dilution was used to prepare a spread plate. After incubation, 58 colonies were present on this plate. What is the CFU/g of the soil sample? Assume: 1 g = 1 mL

Five grams of soil were added to 45 ml of sterile water and shaken vigorously. After that, 0.1 ml of this was added to 9.9 ml of sterile water. This was further diluted by four successive 1/10 dilutions. The last dilution was used to prepare a spread plate. After incubation, 58 colonies were present on this plate. What is the CFU/g of the soil sample? Assume: 1 g = 1 mL

Principles Of Radiographic Imaging: An Art And A Science

6th Edition

ISBN:9781337711067

Author:Richard R. Carlton, Arlene M. Adler, Vesna Balac

Publisher:Richard R. Carlton, Arlene M. Adler, Vesna Balac

Chapter3: Electricity

Section: Chapter Questions

Problem 9RQ

See similar textbooks

Similar questions

50 g of food is homogenized in 450 mL of water. From this, 1 mL is added to 29 mL of water, and then a 1:90 dilution is made from this, and then 1 mL from this is added to 99 mL of water, and then 100 uL of this last dilution is plated and after incubation 164 colonies are counted.a) What was the overall dilution factor?b) What was the total CFU/g of the original sample?
If you plate 200 ul of a 1:100,000 dilution and get 123 colonies, what is the number of CFU/mL in the original sample?
How would you perform a 100-fold dilution, if you want the final volume to be 15mL? What volume of sample and volume of dilute would be used?
The plate with 45 colonies was inocculated with 100 µL Volume of a 10^-8 Dilution. Given the formula OCD = CFU/V x D, what as the Original Colony Density?
How do you calculate the initial concentration of a sample? How would you make a 1:10 dilution of a broth culture if the final volume of the dilution is 10 ml? How much broth, and how much diluent, would you add? If you made a series of tenfold dilutions, exactly the same way as you described in question 1, what would be the dilution factor in the fifth tube? 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…
Mary Jo prepared a series of diluted samples by taking 1 mL of sample and adding it to 4 mLs of diluent. She then diluted the sample further by adding 1 mL of diluted sample to 19 mLs of diluent. What is the final dilution factor ?
"If you count 70 colonies from a urine culture obtained using 0.001ml calibrated loop, how many colony forming units (CFU) will be reported?" 70 700 7000 70000 700000
How would you make two-fold serial dilutions such that the last tube is a 1:32 dilution of the original, concentrated material? Assume that you need to have at least 500 µl of each dilution, and you should be able to perform the dilutions in microfuge tubes with a maximum capacity of 1.5 ml.
You are testing unpasteurized milk for the presence of bacterial contamination. Starting from the undiluted milk, you do serial dilutions, and plate 0.5 ml of 4th dilution on agar. If you counted 78 CFUs from the 4th plate, how many bacteria/ml do you expect? (show solution) Do you think standard plate counts are very accurate? Why or why not?
If there is 50 bacterial colonies on a 1:1000 dilution streak plate. How many cfu/mL are there?
You have prepared the following serial dilution using tryptone broth:d1: 0.1ml culture + 9.9 ml brothd2: 300µl d1 + 4.7 ml brothd3: 0.2ml d2 + 9800 µl broth1) Write your dilutions as a rational number AND in scientific format? What was your total dilution (in scientific notation)?2) What was the original concentration of your culture if you spread 0.1 ml of d3 and counted360 cfu?
A sample of Earth Alive Soil Activator was diluted by transferring 1 gram into a 9 ml dilution blank (tube A) and then serially diluted five (5) more times by transferring 1 ml of a previous dilution into a tube of 9 ml of sterile water. After making these serial dilutions, 2 ml samples were taken from tubes D, E, and F, added into empty petri dishes, and molten PCA was poured into each petri dish. Tubes A, B, and C were heated in a 80˚C water bath for 30 minutes, 2 ml samples of these tubes were added into empty petri dishes, and molten PCA was poured into each petri dish. These plates were allowed to solidify, and they were incubated at 35˚C for 48 hours. After the incubation period, you counted CFUs on all 6 plates. The results of your CFU counts are contained in table 1. Table 1. CFU counts for 3 plates from the heated dilutions (A-C) and the 3 plates from the non-heated dilutions (D-F) # CFUs Not heated Heated A -- 400 B -- 45 C -- 6 D 350 -- E 31 -- F 2 --…