What does it mean that the cell culture flasks are pyrogen-free?

 Cell culture flasks are a type of consumables commonly used in the cell culture process. Cell growth has higher requirements for the environment, and the selection of consumables must also meet the requirements of pyrogen-free. Then, what does pyrogen-free mean?

There are two types of pyrogens. One is the endogenous pyrogen, which acts on the body temperature regulation center of the hypothalamus and is a protein that can raise body temperature. One is exogenous pyrogen, which refers to foreign substances that can be the cause of fever. It usually works by inducing endogenous pyrogens. What we usually call pyrogen-free consumables such as cell culture flasks refers to exogenous pyrogens.

What does it mean that the cell culture flasks are pyrogen-free?

Exogenous pyrogens are mainly bacterial pyrogens, which are metabolites of certain bacteria, bacterial corpses and endotoxins. Gram-negative bacilli have the strongest heat-causing ability, followed by gram-positive bacilli. Gram-positive cocci are weaker. Molds, yeasts, and even viruses can also produce pyrogens. The pyrogen is usually a complex formed by the combination of phospholipid polyol and protein. Phospholipid polyol is the active center of the complex and has the strongest pyrogenic effect. Its chemical composition varies with different strains. The molecular weight is 5×104 to 5×105, and the closer the molecular weight, the stronger the thermal effect. In the cell culture process, if the consumables contain pyrogens, it will directly affect the growth and reproduction of the cells, so these consumables must undergo special treatment to remove possible exogenous endotoxins and ensure the normal growth of cells.

In addition to cell culture flasks, consumables such as micropipettes and matching tips used in cell culture need special treatment to eliminate pyrogens before they can be put into use.

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