In "double tetracycline labeling", a second dose is given 11–14 days after the first dose, and the amount of bone formed during that interval can be calculated by measuring the distance between the two fluorescent labels.
Ao facer o dobre marcado con tetraciclina, adminístrase unha segunda dose de 11 a 14 días despois da primeira, e a cantidade de óso formado durante ese interevalo pode calcularse medindo a distancia entre as dúas marcaxes fluorescentes.