Shake Flask Technology

For more than 150 years, shake flasks are used in research and development as reaction chambers for chemical and microbiological reactions. An uncountable number of experiments has been performed in shake flasks—a suitable tool for laboratory scale—and, therefore, a lot of data and knowledge was achieved. Owing to its simple but advantageous design, the shake—also called Erlenmeyer—flask represents an appropriate tool for cultivation of biomass in biotechnological laboratories. Recently, more engineering efforts have been performed to describe conditions in shake flasks such as gas transfer or power consumption. Further innovative approaches were developed to either enable larger shaking systems for production or monitor growth-related parameters online, and at line. Moreover, disadvantages of this technology such as less regulation and controlling possibilities or limitations in gassing/degassing have to be taken into account. The focus of this article is to give fundamental information about the most important issues in shake flask technology for biotechnological applications. Starting with a short historical introduction, the authors highlight the most commonly used types of different flask and closure types, volumes, etc. Subsequently, functions and the introduction of important shaking-related parameters such as shaking diameter and shaking frequency are given. Before ending up with the innovative potential of modern investigations concerning this significant technology, advantages and disadvantages of shake flask applications are discussed. Keywords: screening; laboratory scale; cultivation system; rotary motion; optimization