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IML OF A 1:1.000 DILUTION SHOWS A COLONY COUNT OF 234 COLONIES. WHAT IS THE NUMB

ID: 166357 • Letter: I

Question

IML OF A 1:1.000 DILUTION SHOWS A COLONY COUNT OF 234 COLONIES. WHAT IS THE NUMBER OF CFU/ML OF THE ORIGINAL SAMPLE?___ IML OF A 1:100 DILUTION IS DILUTED WITH 99ML OF WATER.. 1 OF THE RESULTING DILUTION GROWS 46 COLONIES WHEN PLATED. WHAT IS THE NUMBER OF CFU/ML OF THE ORIGINAL SAMPLE?___ STANDARD PLATE COUNTS ARE INCUBATED AT___DEGREES CENTERGRADE. IML OF A 1:100 DILUTION IS DILUTED WITH 99ML OF WATER. 0.5 01 THE RESULTING ILUTION GROWS 95 COLONIES. WHAT IS THE NUMBER OF CFU/ML OF THE ORIGINAL SAMPLE?___

Explanation / Answer

3. 1 ml of A is diluted by 1:1000 times and gave 234 colonies.

CFU is given by number of colonies * dilution factor

234 * 1000

2.34*105 CFU/ml

4. dilution done in plating is 1:100 then 1ml of this is further diluted into 1:100 out of which 0.1 ml is used so total dilution will be 100*100*10

so CFU is equal to 40*100000

4*106 CFU/ml

5. 37-degree celsius

6. CFU stands for colony forming unit

7. dilution done in plating is 1:100 then 1ml of this is further diluted into 1:100 out of which 0.5 ml is used so total dilution will be 100*100*2

95*100*100*2

190*100*100

1.9*106 CFU/ml