Napsin is a pepsin-like aspartic proteinase, in the A1 clan of the AA clade of proteinases. There are two closely related napsins, napsin A and napsin B. Immunohistochemical studies revealed high expression levels of napsin A in human lung and kidney but low expression in spleen. It is expressed as a single chain protein in type II pneumocytes and in adenocarcinomas of lung. The high specificity expression of napsin A in adenocarcinomas of lung is useful to distinguish primary lung adenocarcinomas from adenocarcinomas of other organs.^1-5

• Visualization: cytoplasmic
• Control: lung adenocarcinoma, kidney
• Dilution Range: 1:100-1:500

References
1. Jagirdar, J. Arch Pathol Lab Med. 2008; 132:384-96.
2. Dejmek A, et al. Diagn Cytopathol. 2007; 35:493-7.
3. Inamura K, et al. Am J Surg Pathol. 2005; 29:660-5.
4. Bishop JA, et al. Hum Pathol. 2010; 41:20-5.
5. Ye J, et al. Appl Immunohistochem Mol Morphol. 2011; 19:313-317.

Type: Primary
Antigen: NAPSA
Clonality: Polyclonal
Clone:
Conjugation: Unconjugated
Epitope:
Host: Rabbit
Isotype: IgG
Reactivity: Human