Erlenmeyer flasks is also known as Conical Flask, This model of flask is also used in microbiology laboratory, especially for the preparation of microbial culture. Conical flasks are mainly put in used for cell culture, which are sterilized as well as might feature vented closures to improve exchange of gases, during incubation either while shaking. The use of very small or slight amount liquid volumes, particularly not in exceed than one fifth of a flask’s total volume respectively, and baffles are molded towards inward direction of the flask's internal surface the reason for both serve to maximize the flow of gas transfer and raise a chaotic mixing, only when the respective flasks are shaken, orbitally. The rate of change or transfer of oxygen in Conical flasks, mainly depends, on the speed of stir-up, the liquid volume of any respective amount.
The frequency of shaking or stirring up does have the most important impact on oxygen transfer. The process of oxygenation and a mixing of cultures of liquid, which further depend on rotation of the liquid "in-phase". Under certain conditions the shaking process leads to a breakdown of liquid motion – called "out-of-phase phenomenon". This phenomenon has been acute characterized for shake flask bioreactors. Out-of-phase conditions are associated with a strong decrease in mixing performance, oxygen transfer, and power input. Main reason for out-of-phase operation is the viscosity of the culture medium, but also the vessel diameter, low filling levels and/or a high number of baffle.
