Tetracycline labeling of bone

Tetracycline labeling is used to determine the amount of bone growth within a certain period of time (approx 21 day period). Osteoid is new bone that has been laid down by the osteoblasts and is non-mineralized. Usually tetracycline is given for several days in a row at 2 time points with a 10 day gap in between the dosing periods. It is recommended that the biopsy not be taken until at least 3-5 days after the last label. The label is incorporated into the mineralized bone and fluoreces under UV light microscopy. Dosing of the tetracyline is dependent on the model (human, rat, rabbit, canine etc.)

The bone must be processed mineralized in order to view the labels. Decalcification of the bone removes the labels. Noel Clark authored 2 papers in the Journal of Histotechnology Vol 25 June 2002 which list some the original authors (Frost & Villanueva) regarding tet labeling. This is a follow-up of a previously published paper (Sanderson, Clark, Bachus) regarding the fixation of tetracylcine labeled bone. If the investigator is interested more in the measuring of osteoid, then staining the sections with Sanderson's Rapid Bone Stain (RBS) or McNeal's Tetrachrome is recommended. The RBS clearly differentiates the mineralized from the non-mineralized tissues in bone that has been processed in plastics. If you check my web site www.wasatchhisto.com there are several papers previously published regarding the RBS and the staining properties.