{"action": "prepare", "output": "", "reagent": ["<<<human periodontal ligament cells>>>"]}
{"action": "maintain", "output": "", "reagent": ["<<<MEM-\u03b1>>>"], "volume": ["<<<approximately 10 mL>>>"]}
{"action": "observe", "output": ""}
{"action": "rinse", "output": "", "volume": ["three to six"]}
{"action": "wash", "output": "", "reagent": ["<<<PBS>>>"], "times": ["<<<2\u20133 times>>>"]}