Why do you invert the culture dish when conducting biological experiments with the culture dish?

When culturing in an inverted Petri dish, since the air in the Petri dish is not easy to flow, the infection of foreign bacteria can be reduced as much as possible, and the contamination of the culture medium and culture by bacteria can be avoided. Through experimental observation, it is found that if the culture dish is placed in the correct direction, it is easy to grow contaminated bacterial colonies around the culture dish. When the culture conditions require ventilation, the inverted culture dish can reduce the air flow on the surface of the culture medium, slow down the evaporation of water in the culture medium, keep the water in solid medium such as agar, and fully maintain the elasticity of the culture medium. Agar and other coagulants can prolong the time of medium rupture. Therefore, reverse culture is conducive to the propagation and survival of bacteria. If the culture dish is placed vertically, the medium will lose water and break in a few days. It can be seen that it is very important to prevent water loss during the cultivation process. When opening the incubator to take out and place the Petri dish, it is easy to knock off the lid of the accidentally placed Petri dish. Although the inverted Petri dish can keep its original shape when it is removed, it is not easy to separate the bottom of the dish from the lid, thus avoiding the contamination of bacteria in the environment. After inverting the culture dish, since the culture medium still has a residual temperature and has just solidified, the water content is relatively high and the humidity is relatively high, and some water drops fall on the dish cover. If the culture dish is placed, the condensed water droplets will flow into the culture medium, which will not only cause pollution, but also separate the culture medium from the culture dish, so that it is easy to slide. This is one of the reasons why the culture medium cannot adhere firmly. If the water in the culture medium is very large when the culture dish is laid, the bacteria in the culture medium will flow around during the inoculation and culture, and the grown bacterial membranes will be connected together and cannot be counted. The main purpose of dish culture is to separate single-cell colonies for observation and identification. Inverting the dish can prevent condensed water from dropping onto the culture medium and being polluted by bacteria. It is also conducive to the growth, reproduction and counting of bacterial species.

When culturing in an inverted Petri dish, since the air in the Petri dish is not easy to flow, the infection of foreign bacteria can be reduced as much as possible, and the contamination of the culture medium and culture by bacteria can be avoided. Through experimental observation, it is found that if the culture dish is placed in the correct direction, it is easy to grow contaminated bacterial colonies around the culture dish.
When the culture conditions require ventilation, the inverted culture dish can reduce the air flow on the surface of the culture medium, slow down the evaporation of water in the culture medium, keep the water in solid medium such as agar, and fully maintain the elasticity of the culture medium. Agar and other coagulants can prolong the time of medium rupture. Therefore, reverse culture is conducive to the propagation and survival of bacteria. If the culture dish is placed vertically, the medium will lose water and break in a few days. It can be seen that it is very important to prevent water loss during the cultivation process.
When opening the incubator to take out and place the Petri dish, it is easy to knock off the lid of the accidentally placed Petri dish. Although the inverted Petri dish can keep its original shape when it is removed, it is not easy to separate the bottom of the dish from the lid, thus avoiding the contamination of bacteria in the environment.
After inverting the culture dish, since the culture medium still has a residual temperature and has just solidified, the water content is relatively high and the humidity is relatively high, and some water drops fall on the dish cover. If the culture dish is placed, the condensed water droplets will flow into the culture medium, which will not only cause pollution, but also separate the culture medium from the culture dish, so that it is easy to slide. This is one of the reasons why the culture medium cannot adhere firmly. If the water in the culture medium is very large when the culture dish is laid, the bacteria in the culture medium will flow around during the inoculation and culture, and the grown bacterial membranes will be connected together and cannot be counted.
The main purpose of dish culture is to separate single-cell colonies for observation and identification. Inverting the dish can prevent condensed water from dropping onto the culture medium and being polluted by bacteria. It is also conducive to the growth, reproduction and counting of bacterial species.