Why petri dishes incubated in an inverted position

A pure or axenic culture is a population of cells or multicellular organisms growing in the absence of other species or types. A pure culture may originate from a single cell or single organism, in which case the cells are genetic clones of one another.

How do you decide which colonies should be picked from a plate culture of mixed flora? Why are agar plates incubated for 24 to 48 hours? For safety reasons, plates and equipment should be sterilised after use.

What would happen to plates poured with agar that is too cool? If the media is too cool, it will start to solidify in the container. If it is too hot, it will leave excess condensation on the lids. Swirl the media again to mix just before pouring; be careful not to incorporate bubbles.

Pour into plate until it covers the bottom, approximately 25 mL see video below. How long do LB agar plates last? This recipe is for mL of LB agar.

This makes about 20 plates 1 bag. Petri dishes can be stored up to three months in cold storage before use in an incubator. Inverted Petri dishes also minimize the evaporation of water used to grow the samples sealed in the containers.

Dishes are sealed with tape so that lids do not fall off when the inversion occurs, and the tape can be written on for labeling purposes. The apparatus can also be stacked for easy storage in an incubator. Petriplates incubated in inverted position First thing is that, media should be poured in to petriplates at specific temperature which means media should not be very hot during testing to cause damage of microorganisms and media should not be cool to become solidified before pouring.

During incubation, media contains moisture and if petriplates are incubated in upright position then moisture will evaporate from the media and that moisture condense on the lid in form of droplets. Moisture on lid of the Petriplate When condensed moisture fall on the media plates then it can cause spreading of microbial colonies and it would be difficult to count the number of colonies properly. So, to prevent this petriplates are incubated in an inverted position.

He covered one culture plate to another plate to prevent the contamination. Before him, the culture plates were covered with the glass bell jars. All of we know that the Petriplates are incubated in inverted position but this question arises in our mind that why these plates are incubated in inverted position?

I got many questions daily from pharmaceutical professionals and this question is asked very frequently. There are following advantages during incubation when we incubate the plates in inverted position. When the plates are incubated in the normal position, water evaporation from media occurs. These vapors condense on the lid of the Petri dish and drops fall on the colonies developed on the media surface.

This causes colony mix-up with each other and spread throughout the plate surface. This creates the problem in counting and proper determination of microbial count. 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.