The ClonaCell™-CHO ACF supplement improves cloning efficiency of CHO cells during cell-line development. The challenges of low cloning efficiency can result in significant waste of time and resources during single-cell cloning. The ClonaCell-CHO ACF supplement is designed to address this issue by promoting efficient single-cell expansion of CHO cells. This product is a 40X defined, serum-free, and animal component-free CHO cell culture media supplement that, when added to a range of protein-free media, delivers cloning efficiency similar to cloning in serum-containing media.