Alpha-naphthyl Butyrate Esterase

**Semantic type:** Amino Acid, Peptide, or Protein|Enzyme|Indicator, Reagent, or Diagnostic Aid

**Definition:** A selective cytochemical monocyte marker for alpha-naphthyl butyrate at pH 6.1. Alpha-naphthyl butyrate covers the external surface of the plasma membrane in monocytes and membrane-bounded intracellular organelles in lymphocytes.