Scientists are developing new methods of treating men with reproductive problems. Research is conducted at the experimental level. Stem cells are isolated and cultivated in laboratory conditions. The spermatozoa are grown in a test tube from cells taken from the testicles of experimental mice. They are then injected into eggs. Subsequently, 12 babies were born – 4 from males and 8 from females. All of them are completely healthy and able to reproduce in their mature age. Experts explain that the process of sperm formation is one of the most complex in the human body. It has never before been replicated in a test tube. The scientists achieved success by mixing the cellular components and stem cells, then watching them turn into sperm. Scientists then use in vitro techniques to create offspring. Testicular tissue is frozen in liquid nitrogen. In this way, it is kept healthy and used over time. Such a method would be beneficial for young men or boys who need radiation or chemotherapy. The tissue could be harvested before treatment, frozen and used later for a reproductive problem. According to the scientists, the research is a small but important step in understanding how sperm are formed, which could eventually lead us to be able to “grow” them in laboratory conditions.