A new look at formalin fixation for fluorochrome labeled bone

For approximately 30 yr, laboratories studying dental and bone diseases suc h as osteoporosis, osteomalacia, or orthopedic implant devices have used fl uorochrome labels to measure the mineral apposition rate. Fixation of the b one with 10% neutral buffered formalin has been routinely used by many of t hese laboratories. Routine custom has been to fix the bone specimens in for malin for no more than 48 hr, wash them in water, and place them in 40-70% ethanol for further fixation and/or storage. This paper reports a study tha t demonstrates fixation of bones for up to 90 days in 10% neutral buffered formalin caused no evident loss of the fluorochrome labels.