WB; IH,Frozen; IH(P), Paraffin Immunohistochemistry (IHC) and Western Blotting (WB). A concentration of 0.5-1.0 µg/mL is recommended for WB. The predicted length of human cathepsin D is 412 aa. The predicted MW is 34 kDa (active) and 52 kDa (precursor). A concentration of 1.0-2.0 µg/mL is recommended to detect cathepsin D in paraffin embedded tissues. Antigen retrieval by heat is required. Biosensis recommends optimal dilutions/concentrations should be determined by the end user.