Objective To search for the best generation of the nucleus pulposus cells suitable as seed cells in tissue engineering, which come from the nucleus pulposus tissues of anterior cervical operation, and study the effects of cryopreservation and recovery process on type Ⅱ collagen synthesis and proliferation of nucleus pulposus cells. Methods The mean optical density of the first, second, third, fourth and fifth generations of nucleus pulposus cells in immunohistochemical staining photographs was measured, so ...