5. River water samples are diluted to 10^-2, 10^-3, and 10^-4. You plate 500μl of each dilution, incubate overnight, and find that only the 10^-4 plate had isolated, countable colonies; however, colonies on the other plates are “Too Numerous To Count” (TNTC). (a) Calculate the CFU/mL if you counted 100 colonies on the 10^-4 plate. Show your work. (b) State a modification you could make to the protocol in order to obtain isolated, quantifiable colonies on all three agar plates.

5. River water samples are diluted to 10^-2, 10^-3, and 10^-4. You plate 500μl of each dilution, incubate overnight, and find that only the 10^-4 plate had isolated, countable colonies; however, colonies on the other plates are “Too Numerous To Count” (TNTC). (a) Calculate the CFU/mL if you counted 100 colonies on the 10^-4 plate. Show your work. (b) State a modification you could make to the protocol in order to obtain isolated, quantifiable colonies on all three agar plates.

Curren'S Math For Meds: Dosages & Sol

11th Edition

ISBN:9781305143531

Author:CURREN

Publisher:CURREN

Chapter9: Parenteral Medication Labels And Dosage Calculation

Section: Chapter Questions

Problem 1.2P

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Similar questions

2. a) Calculate the CFU present in 100 mL water sample and b) dilution factor in Tube 5. Consider the following dilution scheme: 5 ml 1 ml 0.5 ml 1 ml 0.1 ml 0.9 ml Water sample 9 mL 4.5 mL 100 μL 100 ml 45 ml 19 ml 100 ul 100 ul 100 μι 100 μL No. of colonies: TNTC 425 58 12 1 3.
Serial dilution = previous dilution x dilution 11 mL [2] 3 mL Colony count: 100 0.1 mL sample [1] 9.9 mL 5 mL 0.1 ml. Cokony count Dilution: 10-1 10-3 [3] 150 Dilution factor (DF): [4] [5] [6] Compute for the CFU/mL of the sample. Show your solution and express your final answer to 2 significant figures.
6) 1 mL of supernatant is required for a procedure. The final colored solution proves to be too high to read accurately on the spectrophotometer. 100 μL of supernatant and 900 μL of distilled water are substituted for the original supernatant and the procedure, run as before. The reading from the standard curve is 46 mg/dL. What is the actual amount of substance in the patient serum?
A urine sample is diluted 1:1,000. If 0.1 ml were put into a Petri dish with melted agar, how many CFU/ml are in the urine if 158 colonies grow?
An original sample of water containing 4.00 X 106 CFU/mL was diluted by 4 successive 1/10 dilutions. After incubation, 200 colonies were found growing on the plate. How many mLs from the last dilution tube were plated out?
2. a) Calculate the CFU present in 100 mL water sample and b) dilution factor in Tube 5. Consider the following dilution scheme: (20 pts.) 5 ml 1 ml 0.5 ml 1 ml 0.1 ml 0.9 ml Water sample 9 mL 4.5 mL 100 μL 100 ml 45 ml 19 ml 100 ul 100 ul 100 μι 100 μL No. of colonies: TNTC 425 58 12 1 3.
Explain this example of the following water quality serial dilution. Note the dilution factors and how you would calculate #’s from the incubated plates. ……A serial dilution yielded TNTC in the 1:1 plate and the 1:10 plate, 50 cfu’s in the 1:100 plate and 3 cfu’s in the 1:1000 plate . What is the concentration (CFU)/ml of the raw sample? Is water acceptable for potable or Recreational use? Explain. When do you use filtration rather than serial dilution
An original sample of water containing 4.20 X 109 CFU/mL was diluted by 4 successive 1/100 dilutions. Exactly 1 mL from the last dilution was used to prepare a pour plate. After incubation, how many colonies were present on this plate?
one lm of milk was added to 9 ml of sterile saline. 0.1ml of the diluted sample was put into a petri dish with melted agar. How many cfu/ml are in the milk if 200 colonies were counted?
I have another one, 1 ml of sewage water is added to 9 ml of water. 0.1 ml of this is added to 9.9 ml of water. 1 ml of this is then added to 9 ml of water. 1 ml is plated and 243 colonies form. What is the CFU/ml of the sewage water? Thanks again.
Explain this example of the following water quality serial dilution. Note the dilution factors and how you would calculate #’s from the incubated plates. ……A serial dilution yielded TNTC in the 1:1 plate and the 1:10 plate, 10 cfu’s in the 1:100 plate and 1 cfu’s in the 1:1000 plate . What is the concentration (CFU)/ml of the raw sample?
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.