Alizarin red S for calcium
Use a positive control section.
- Dewax sections, rinse in alcohol, rinse in water.
- Rinse in distilled.
- Filter on alizarin red solution and leave for - 1 minute.
- Blot dry then rinse in acetone - 30 seconds.
- Rinse in acetone/Histo-Clear® (or acetone/xylene) 1:1 - 15 seconds.
- Rinse in Histo-Clear (or xylene) and mount.
Calcium deposits - orange/red.
Alizarin red solution
Alizarin red S- 2g
Distilled water - 100mls
Adjust pH to approx. 4.2 with 10% hydrochloric acid then with 10% ammonium hydroxide if it goes below.
If there is any doubt that the resulting red staining is calcium a negative control (to remove calcium) can be performed. This is done by placing a second test section in 10% formic acid for 10 minutes prior to step 3, rinsing well in distilled water and continuing with the technique.