I have difficulties in solubilizing tetracycline hydrocloride to label rat bone. The concentration I'm using is 15 mg/ml in physiological saline: doesn't solubilize well. Any suggestion? What if I use distilled water, do I risk to harm the rats?
Have you considered calcein (green), xylenol (orange) and alizarin (red)? These may be better options to tetracycline as they cause less impairment to bone growth and mineralization.