Linear scale-up is the most common principle used in process scale-up. By linear scale-up, we mean that we can obtain almost uniform chromatographic results from laboratory scale to pilot results or industrial production level. The core idea is to keep the column height and linear flow rate constant and only scale up the column diameter and volume flow rate. A fixed column height and linear flow rate theoretically ensures the same retention time, the number of CVs used in chromatography and the number of CVs of the eluted sample, maximizing the same purification results. Theoretically, this linear scale-up of the purification separation behavior should be very similar, thus ensuring a successful scale-up of the chromatographic process. However, some additional factors need to be considered, including a decrease in column tube support (increased pressure drop), column efficiency/column bed instability, sample diffusion (peak spreading), and dead volume of the system and tubing.