Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

DATA SHEET 6-1 Name Date Lab Section I was present and performed this exercise (

ID: 132207 • Letter: D

Question

DATA SHEET 6-1 Name Date Lab Section I was present and performed this exercise (nitials) (continued) 11 Plating 1.0 ml of a sample diluated by Plating 1.0 ml of a sample diluted by a factor of 10-1 produced 43 colonies, What was the original cell density in the sample? 12 P Plating 0.1 ml of a sample diluted by a factor of 1O 1 produced 43 colomies What was the original cell density in the sample? 13 A plate with a sample volume of 10- ml produced 72 colonies a. What was the original cell density b. How many colonies should be on the plate imoculated with a sample volume of 10"s mL c. How mamy colonies should be on the plate imoculated with a sample volume of 10 mL 14 A plate with a sample solume of 10 *ml,produced 259 colomies a. What was the original cell density? b. How mary colonies should be on the plate inoculated with a sample volume of 10- mL c. How many colonies should be on the plate inoculated with a sample volume of 10-7ml A mutrient agar plate that received 1,000 ul of a bacterial sample diluted by a factor of 10& had 298 colonies on it after incubation. What was the original cell density?

Explanation / Answer

11) One mL of the solution diluted by a factor of 10^-3 produced 43 colonies.

The original cell density in the sample is calculated by the formula,

= number of colonies /dilution factor

= 43/10^-3

= 43 x 10^3

= 43000 CFU/mL

The cell density present in the original sample is 43000 CFU/mL

12) 0.1 ml of sample diluted by a factor of 10^-3 produced 43 colonies.

Therefore, the original cell density is,

= 43/10^-3 per 0.1 ml

= 43 x 10^3 per 0.1 ml

= 43 × 10^4 CFU/mL

Please post other questions separately.