6, Bacteria/mL = No.of .colonies x dilution factor/ volume of culture plated
= 200 x 103/ 0.1
=200 x 104
= 2 x 106 bacteria/mL
7, The colony count in the plate must lie between 30-300 colonies inorder to be considered countable
6) How many bacteria would be in 1 ml of the original sample if the 108...
17. A sample of a culture of bacteria is subjected to 10-fold serial dilution; 0.1 mL aliquots of the dilutions are grown on agar plates and the number of colonies counted: Dilution: Number of colonies: 10- Too many to count 10-6 10- 2 0 -3 Too many 249 to count 10-4 24 2 10-5 0 BIOT 5021-SP2 Assuming that one cell gives rise to one colony, how many cells were there per mL of the original culture?
A polluted water sample has 2,400,000 bacteria per ml. You transfer 1.0 ml of sample to a bottle containing 99ml of sterile water. You then take 0.1 ml from this dilution bottle and transfer to a second bottle with 0.9 ml of sterile water. Finally, you transfer 1 ml to a Petri dish with nutrient agar. How many colonies would you expect to find on this plate? Would it be countable?
Two parallel dilution series were made from the same original sample. The plates with sample volumes of 10- mL from e ach dilution series yielded 144 and 93 colonies. Suggest reasonable sources of error. What are the only circumstances that would correctly produce countable plates from two different dilutions?
(A) You have a sample with an original concentration of 1.0 x 10^7 CFU/mL. With the Plate Count Method, what final dilution factor would be needed to produce countable plates? Show your work. (B) Describe a dilution scheme (how many tubes, what volume in each tube, what DF is achieved in each step) that uses only the 9-mL blank diluent tubes to achieve the dilution needed for this FDF.
1)How many microliters of original sample are required to produce a final dilution of 10-2 in a total volume of 5 mL? 1 microliter is 10-6 L or 10-3 mL. 2)A 0.00001 dilution is performed on a culture of bacteria in order to perform viable plate counts. From the dilution, *0.1 mL* of solution is plated on solid media, and 197 colony forming units grow on the plate. How many bacteria are in a single mL of the original culture?...
You are given a fresh meat sample containing 5.6 times 10^5 bacteria/g. Diagram how you would dilute and plate this sample so that you that the resulting plates have colony numbers in a countable range. Predict how many colonies would be present on each plate.
How many CFUs are in the original sample with a dilution of 1/100,000, and 63 colonies.
how many cells/ml are in the original sample?
can you please explain
5 ml 10 ml 5 ml 1 ml 0.1 ml 1 ml - 25 cfu 495 ml 990 ml 9 ml 45 ml 200 cfu Bacteria Bacteria
Suppose a broth has 436 million bacteria per milliliter. A serial dilution is made using three bottles of 99 milliliters each. 1mL is transferred from the sample to the first bottle; 1 mL is transferred from the first bottle to the second; and then 1 mL is transferred from the second bottle to the third. From the third bottle 0.1 mL is transferred to pour plate. How many colonies would you expect to find on the plate? Show your work.
2. A series of 1 ml samples from tube #4 of the dilution s eries below are spread on agar plates, resulting in the growth of an average of 68 colonies per plate. What is the concentration of colony-forming units (cfu/mi) present in the original culture? 0.1 ml 0.1 ml 1 ml 1 ml 100 ml 9.9 ml 9.9 ml 9 ml 9 ml 2 4 3. The culture flask at left contains a total of 3.2 x 10s cfu....