You attempted to determine the number of bacteria in a culture using the Turbidimetry method with a spectrophotometer and obtained the following data: Sample Optical Density Uninoculated Media only 0.054 1:16 dilution of culture 0.412 1:8 dilution of culture 0.964 1:4 dilution of culture 1.815 1:2 dilution of culture 2.450 1:1 dilution of culture 2.860 Using the formula below: OD600 of 1.0 = 8 x 108 cells/ml
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- You prepared 10-7, 10-8, and 10-9 dilutions of a bacterial suspension in sterile saline. Then you plated 0.15mL if each dilution onto each of 3 plates of nutrient agar. After incubation, the colonies were way too numerous to counton the plates prepared from the 10-7 dilution. The plates from the 10-8 dilution had 355, 360, and 350 colonies. The platesfrom the 10-9 dilution had 115, 117, and 118 colonies. Determine the concentration of colony forming units (cfu/mL) inthe original bacterial suspensionA serial dilution of a bacterial culture yields the following number of colonies. Which plate(s) should be used to determine the original cell density? Plate A Plate B Plate C Plate D Plate E Dilution Factor 10-5 10-6 10-7 10-8 10-9 # of Colonies Too many to count 850 456 80 14 Group of answer choices All of these choices A & B D & E E None of these choices A B & C D B C & D CYou begin with an overnight culture of approximately 108 organisms/ml and need a concentration of 103 bacteria/ml in order to get a countable spread plate. Describe how you would dilute your sample.
- This is a Microbiology question about blood culture analyzers such as the BactecWhat is the process a technician takes if the analyzer alarms for a positive bottle?What action(s) are taken if there are no organisms seen in the Gram Stain made from that bottle?You are hired in one of the microbiology labs in Memphis and your first assignment to identify microbial samples from a local restaurant. You are given a set of slides and asked to classify the specimens as Gram positive or Gram negative. Based on this information answer questions 1-10: 6) What would be the last reagent you use to identify the bacteria?7) What type of visual aid you need to help you see the bacterial samples clearly?8) After the use of what reagent, you will be able to decide if you have a Gram positive or Gram negative bacteria?A 10-5 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 278 colony forming units grow on the plate. How many bacteria are in a single mL of the original culture? Express your answer to two decimal places using scientific notation. In scientific notation 540 would be written as 5.40*10^2. Since only 0.1 mL is put on the plate, this counts as an extra dilution!!! Any time less than 1 mL is transferred, a dilution is being performed. Any time more than 1 mL is transferred, a concentration is being performed. Include the trailing zero so there are two decimal places Canvas expects a single digit before the decimal point. 5.40*10^2 is how Canvas expects 540 to be formatted in scientific notation 54.00*10^1 would be marked wrong. 0.54*10^3 would be marked wrong. A 10-5 dilution is performed on a culture of bacteria in order to perform viable plate counts. From the…
- Describe how you would make 10 ml of a 1:500 dilution of bacteria by performing TWO SEPARATE DILUTIONS in series? Consider the accuracy of the pipetting so that you don’t make a single dilution that is too large.a pure bacterial culture was diluted by adding a 0.2 mL aliquot to 0.9mL water. Then 0.1 mL of this dilution was plated out, yielding 82 colonies. Calculate the CFU/mL in the original culture.A 2x10-6 dilution of your bacterial culture yielded 10 colonies. What was the cell density (incells/ml) of your bacterial culture?
- thirty-six colonies grew on nutrient agar plates when 1.0ml of a 1/10 dilution of a water sample was plated using the standard plate count methodology. How many bacteria were in the original water sample? a.4/ml b.36000/ml c.360/ml d.36/ml e.3600/mlA microbiology student was given a mixed culture of two different gram positive bacteria species to grow into a culture medium using correct aseptic techniques. After two days,one gram positive bacterial species grew on the media and the growth appeared red on the surface of the medium. Tthe second gram positive bacterial species grew and the growth appeared yellow on the surface of the medium. What is the possible explanation for the differences in the color of the bacterial growth? A. the culture was contaminated B. the microbiologist put too much inoculum on the culture medium C. the medium was a selective medium D. the medium was differentialUsing a dilution series is a way to transfer the very small volumes of original culture necessary to get countable colony forming units. If you suspect your culture of bacteria has 59.62*10^9 cells per mL, how many mL of original culture would you want to end up on the plate to produce 68 cfu? Express your answer in scientific notation rounded to two decimal places. Eg. 0.01001 would be 1.00*10^-2 You must include trailing zeros 0.0000040001 would be reported as 4.00*10^-6 There must always be two decimal places, even if they are zeros Canvas expects one digit before the decimal point 0.40*10^-5 would be marked incorrect for 0.0000040001