Hi,
Here is another method for staining bone cell, this time Osteoclasts.

I used the TRAP method for Osteoclast staining.
As previously described in the ALP method, the bone should be frozen and then cut to 10um wide samples.

Tartrate-resistant acid phosphatase (TRAP) was determined
by the azo-dye coupling method.
The incubation medium consisted of
alpha-naphthyl phosphate and Fast Violet B dissolved in 25 ml
of 0.05M Na acetate buffer (pH 5) containing 0.05M
sodium tartrate (Sigma). Sections were incubated for 60
minutes at 37°C, rinsed in reaction buffer (acetate buffer pH5), postfixed and
mounted as described in the ALP method.
The section can be counter stained preferably by methyl green.

Guy