24882
When using double staining with Alizarin red for mineralized matrix and Alcian blue for cartilaginous matrix , we observed previously that mineralization was totally absent at embryonic day 15 . 5 throughout the body in Runx2 ( - / - ) mice , but was found in areas undergoing intramembranous ossification such as skull and clavicles in alpha 1 ( II ) - Cre ; Runx2 ( flox / flox ) mice .
 Alizarin red, Alcian blue
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Alizarin red, Alcian blue