The pH of retrieval solution at high temperature can be critical for proper immunohistochemical (IHC) staining. Solutions pH as the temperature rises. The pH of citrate-based retrieval solution increases as the temperature rises. To assure quality control and consistent IHC staining, BIOCARE has developed heat-tested pH strips that give accurate and the true pH at high temperatures. The pH of a solution should be recorded at the temperature used. The laboratory investigator can now record pH on a daily basis, and comply with CAP and JCOH inspection.