Specificity: The rat monoclonal antibody IM7 reacts with CD44 antigen (Phagocyte glycoprotein 1), an 80-95 kD transmembrane glycoprotein (hyaladherin family) present on the most of cells and tissues (leukocytes, endothelial cells, mesenchymal cells, etc.); it is negative on platelets and hepatocytes. The antibody reacts with all isoforms of mouse CD44.