Regenerative medicine, which is still only a hope, consists in repairing a lesion or a diseased organ by replacing the damaged parts with new cellular tissue created for the occasion. It is based on cell therapy, which consists in cultivating cells before transplanting them, and on the use of stem cells, i.e. undifferentiated, like those that make up the very young embryo, or dedifferentiated. These cells are called pluripotent because they can then be transformed into different cell types. Applications include the reconstruction of neuronal tissue affected by neurodegenerative diseases, or of liver tissue to treat liver pathology. Regenerative medicine could reconstitute a damaged part of the spinal cord or regrow adult teeth. As far as my thesis is concerned, I'm highlighting the most widely used technique in regenerative medicine, ELISA.