You perform a serial dilution of a water sample and the 10-7 tube when 0.1 ml was plated onto the nutrient agar plates after incubation and gave you 24 colonies. What is the CFU/ml? What is a 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 --…

A laboratory technician performed a series of 10 fold serial  dilutions shown below. he plated 0.1 mL from each dilution tube onto NA and got the follow numbers per plate dilution 1:10 1:10 1:100 1:1000 1:10000 1:100000 colony count >1000 >1000 808 303 38 3 calculate the concentration of bacteria in the undiluted stock (in CFU/mL)

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?