This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
[{'content': 'The rate of newly synthesized osteoid mineralization can be best estimated by - \nSelect and explain. \nA. Tetracycline labeling, B. Alizarin red stain, C. Calcein stain, D. Van kossa stain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tetracycline labelling for osteoid mineralization\n\nTetracycline labelling is the method of choice for estimating newly synthesized osteoid mineralization in human.\nTetracycline is incorporated into new areas of osteoid that are being laid down but not yet mineralized (osteoid seams)\nTo estimate the rate of newly synthesized osteoid mineralization tetracycline is administered to the subject at two defined time points.\nIf the time interval between the two courses is known, both the rate and extent of mineralization can be measured.\nTetracycline labelling allows a distinction to be made between defective mineralization (osteomalacia) and increased osteoid synthesis (bone remodelling states) by revealing the calcification front.\n\nOther stain used for osteoid mineralization\n\nOther stains can also be used for this purpose, but they are inferior to tetracycline:\xa0\n\n\nAlizarin red\nCalcein\nVon-Kossa', 'role': 'assistant'}]