Confirmation of clonality is a critical step in the generation of biopharmaceutical cell lines. With superior bright field image quality, the Celigo cell imaging cytometer reliably visualizes individual cells in a well, even if the cell is adjacent to the well wall. The Celigo allows for verification that a clone originates from a single cell. Typically, limiting dilution is performed in multi-well plates which are then repeatedly imaged on the Celigo over a period of time. When colony growth is seen after a few days of culture, it is then possible to retrospectively confirm that it grew out of a single cell.