Nucleus replacement devices are a new and experimental treatment technique for spinal disc herniation and degenerative disc disease, offering a potentially minimally invasive, reliable, and long lasting alternative to existing treatment methods. To effectively test the mechanical characteristics of nucleus replacement devices, we designed a test fixture in concordance with SeaSpine and in adherence with the ASTM-F2789-10 Standard.  The design for this fixture, done on Autodesk Fusion 360, consists of a base plate and water-tight chamber in line with a load cell and top plate, and assembly was done using a combination of 3D printed parts and components ordered from McMaster Carr. Testing for lifting force and swelling were performed using sponges as stand-ins for a nucleus replacement, and it was concluded that the fixture properly performs its desired function. Future work is to automate the movement of the top plate, implement a drainage system, and run tests with a real nucleus replacement.