As the workhorses of life, proteins fulfil a variety of functions in our bodies. If their functionality is limited or missing, diseases can arise. Therefore, proteins and their production are a central key to research. Whether protein expression is to be controlled for experimental, biotechnological, or medical applications, the use of cells is often mandatory. Many researchers repeatedly face the same challenge of producing complex target protein fast and cheap. Transient transfection of recombinant plasmids (rpDNA) in mammalian cells is a popular method for this purpose. In the following article, we look at the success story of research assistant Damian von Blarer, who must produce specific regions of the famous SARS-CoV-2 spike protein for efficiency studies of a rapid test – for this he needs plasmids, and we show which questions you need to answer to produce and amplify them easily yourself.