While generating these cells, scientists need a means of determining whether these cells are good. There is no standard battery of tests that will measure the cell's fundamental properties. There are no tests that scientists used to acknowledge any of the indicators of the cell's most important biological properties and functions. Some tests include growing and sub-culturing the stem cells for many months. This ensures that the cells are capable of long-term self renewal. They use specific techniques to determine the presence of surface markers that are found only on embryonic stem cells. Also if the protein OCT 4 is present then they are the correct cells. If the cells are frozen, the thawed, then sub-cultured again and they do reproduce, then they are good as well.
There is also another type of stem cell out there that might confuse society. Those are called adult stem cells. These are undifferentiated cells found among differentiated cells in a tissue or organ; also they can renew themselves as well. These cells only have the ability to re-create cells from the organ or tissue they were extracted from. Most scientists use the term somatic stem cells instead of adult stem cells. The hard thing to believe is that the origin of adult stem cells in mature tissues is unknown. Adult stem cells have been thought of being used in transplants such as: heart, lung, liver, and kidney. Adult blood forming cells from bone marrow have been used in transplants for over the last 30 years. These types of stem cells also have the ability to be controlled in the laboratory to help with therapies for many serious diseases.
Almost 40 years ago was when the first adult stem cells were introduced. Scientist's found these cells in bone marrow. Hematopoietic stem cells form all the types of blood cells in the human body; the other is bone marrow stromal cells. These were discovered a few years later.