laboratory diagnostic - others - NTx - N-telopeptides of type I collagen - urine, 1st or 2nd Early morning urine 5ml. The urine must be frozen within 4 hour after collection and must be sent in the frozen samples container(!).Fasting sample. The urinary creatinine will be tested systematically on the same sample (SFBC recomendations). The sampling method chosen must be retained in repeat prescriptions, Enzyme-immunoassay, ssso, todylaboratories®, bmn, code L16LD1644