Table of Contents
- 1 What plates are incubated upside down?
- 2 Why are petri dishes inverted during incubation quizlet?
- 3 Why must the loop be flamed before entering a culture?
- 4 Why are you instructed to write only on the back of the plate and never on the lid?
- 5 Who was the first person to use a petri dish?
- 6 Why are agar plates used in petri dishes?
What plates are incubated upside down?
Petri plates are incubated upside-down to lessen the risk of contamination from airborne particles settling on them and to prevent the accumulation of any water condensation that may otherwise disturb or compromise a culture. Petri dishes are also used for eukaryotic cell culture in a liquid medium or on solid agar.
Why are petri dishes inverted during incubation quizlet?
Why are petri dishes inverted during incubation? Prevent condensation falling onto microbes thereby contaminating samples. – To minimise contaimination from extraneous bacteria.
Why is the cover of the petri dish not immediately lowered?
During storage (in refrigerator, but not to freeze) the agar plates should be placed in an inverted position with the lid at the bottom. This prevents the condensation from dripping down on to the surface of the agar, which may allow for the movement of the organisms from one colony to another.
How do you remove condensation from a petri dish?
Another commonly practiced technique is to take a jar, something wider than your petri dish and fill it with hot water and once you’ve poured your stack of dishes, put the jar of hot water on the top dish and leave it all to cool.
Why must the loop be flamed before entering a culture?
Why is the loop flamed before it is placed in a culture tube? The loop is flamed before entering a culture tube to ensure that no contaminating microbes are introduced in to the culture. The loop is flamed afterward so that no culture microorganisms are introduced into the working environment.
Why are you instructed to write only on the back of the plate and never on the lid?
Why were you instructed to write only on the back of the plate & never on the lid? Because the lid could fall or it could move causing the marks to get moved to the wrong place & data would be messed up. Also agar isn’t on the lid, nothing will grow. Why did you place the plates upside down in the incubator?
Why are petri dishes stored in an inverted position?
The evaporation of water from media can cause media dryness that can affect the microbial growth but when the plates are incubated in an inverted position, the rate of evaporation decreases that results in proper microbial growth. Therefore, Petri dishes with media can also be stored for a longer period in an inverted position.
Why are Petri plates incubated upside down for Microbiology?
Petri plates are incubated upside down (agar on top) to lessen the risk of contamination from settling airborne particles and to prevent water condensation from accumulating and disturbing the cultured microbes.
Who was the first person to use a petri dish?
Petri dishes were first used by German physician Julius Petri in 1887. He covered one culture plate to another plate to prevent the contamination. Before him, the culture plates were covered with the glass bell jars.
Why are agar plates used in petri dishes?
Agar plates are Petri dishes that contain a medium suitable for culturing microorganisms. They may also be called blood agar plates when they contain red blood cells, often from a horse or sheep, which are often used as a nutrient.