What laboratory tests are used to identify embryonic stem cells?
At various points during the process of generating embryonic stem cell lines, scientists test the cells to see whether they exhibit the fundamental properties that make them embryonic stem cells. This process is called characterization. Scientists who study human embryonic stem cells have not yet agreed on a standard battery of tests that measure the cells’ fundamental properties. However, laboratories that grow human embryonic stem cell lines use several kinds of tests, including: • Growing and subculturing the stem cells for many months. This ensures that the cells are capable of long-term growth and self-renewal. Scientists inspect the cultures through a microscope to see that the cells look healthy and remain undifferentiated. • Using specific techniques to determine the presence of transcription factors that are typically produced by undifferentiated cells. Two of the most important transcription factors are Nanog and Oct4. Transcription factors help turn genes on and off at the r
