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1. What is the purpose of inverting inoculated plates during incubation?
2. Where should colonies appear in the case of : a. Streak plate b. pour plates
3. Indicate the temperature ranges for the following microbial categories.
a. psychropiles b. mesophiles c. thermopiles
4. What factors could account for an absence of growth on a pour plate?
5. What factors could account for an absence of growth on a streak plate?
6. What explanations could be given for the failure of obtaining isolated colonies on a streak plate?
7. Gelatin and Agar comparison:
a. Chemical composition b. temperature required for melting and solidify
c. Possibility of enzymatic attack by bacteria, Yes or No.
What else can I help you with?
What was the purpose of incubating the unopened agar plates?
Incubating unopened agar plates helps create conditions suitable for bacterial growth. This is important for allowing any contaminating bacteria to multiply and be detected at a later stage through observation of the developed colonies.
Why do you incubate plate upside down?
Incubating plates upside down prevents condensation from forming on the agar surface, which could potentially lead to contamination and interfere with bacterial growth. Additionally, it minimizes the risk of accidentally disturbing the agar surface or causing the culture to slide when stacking plates.
What function has glucose in Plate count agar?
Glucose in Plate Count Agar provides a carbon source for microbial growth. It serves as an energy source for bacteria to proliferate and form visible colonies on the agar plate.
What is the name of the streak when you apply specimen to agar plate?
The process of applying a specimen to an agar plate to grow colonies is known as streaking. This technique involves using an inoculating loop to spread the specimen across the surface of the agar in a pattern that promotes the isolation of individual colonies for further study.
Why is the streak-stab technique preferred rather than incubating the plates anaerobically?
The streak-stab technique is preferred over incubating the plates anaerobically because when isolating colonies allows biochemical testing to be performed. When the plate is incubated anaerobically it lacks oxygen and can not be biochemically tested.
What was the purpose of incubating the unopened agar plates?
Incubating unopened agar plates helps create conditions suitable for bacterial growth. This is important for allowing any contaminating bacteria to multiply and be detected at a later stage through observation of the developed colonies.
Where should a label written on an agar plate?
On the base of the agar plate.
Why do you incubate plate upside down?
Incubating plates upside down prevents condensation from forming on the agar surface, which could potentially lead to contamination and interfere with bacterial growth. Additionally, it minimizes the risk of accidentally disturbing the agar surface or causing the culture to slide when stacking plates.
Where should a label be written on an agar plate?
Labels should be written on the bottom of the agar plate. Write the label using a marker on the agar side, being careful not to write on the lid or cover of the plate. This ensures that the label remains visible and does not interfere with the growth of microorganisms on the agar surface.
What does it mean to inoculate an agar plate?
Inoculating an agar plate refers to transferring microorganisms onto the surface of the agar using a sterile inoculating loop. This allows the microorganisms to grow and form visible colonies that can be studied or identified.
What function has glucose in Plate count agar?
Glucose in Plate Count Agar provides a carbon source for microbial growth. It serves as an energy source for bacteria to proliferate and form visible colonies on the agar plate.
How do colonies on the surface of a pour plate differ from those suspended in agar?
How do colonies on the surface of a pour plate differ from those suspended in the agar?
What is the name of the streak when you apply specimen to agar plate?
The process of applying a specimen to an agar plate to grow colonies is known as streaking. This technique involves using an inoculating loop to spread the specimen across the surface of the agar in a pattern that promotes the isolation of individual colonies for further study.
Which method often results in colonies developing down throughout the agar and some colonies on the surface?
The pour plate method often results in colonies developing both down throughout the agar and on the surface. This is because the pour plate involves mixing the bacteria with the agar before pouring it into the plate, allowing for colonies to form at different depths within the agar.
What are the differences between an agar plate and a Petri dish in microbiology experiments?
An agar plate is a specific type of Petri dish that contains a solid growth medium called agar. Petri dish is a broader term that refers to any shallow, flat, circular dish used in microbiology experiments. The key difference is that an agar plate contains agar as a solid medium for microbial growth, while a Petri dish can be used with various types of media, including agar.
Why is the streak-stab technique preferred rather than incubating the plates anaerobically?
The streak-stab technique is preferred over incubating the plates anaerobically because when isolating colonies allows biochemical testing to be performed. When the plate is incubated anaerobically it lacks oxygen and can not be biochemically tested.
Why is it important to write on the agar side of the agar plate?
It is important to write on the "Agar side" of the plate because 1. you do not want your writing on the lid to interfere with your observations and 2. If you lose the lid you won't know what you streaked (what your wrote on the lid).Hope this helps!
