Researchers use various tests to identify stem cells at different points of the stem cell line generation process. These tests may include: 

• Checking the rate of cell proliferation
• Confirming the expression of multiple genes that are known to be pivotal to the functioning of stem cells
• Verifying genome integrity by studying the chromosomes of selected cells
• Validating the cells’ differentiation potential by eliminating signals that allow the cells to remain in their undifferentiated state or introducing signals that encourage stem cells to differentiate into relevant cell phenotypes