Published customer image: . Mouse anti Influenza A nucleoprotein antibody, clone 1341 used for the identification of influenza protein in tracheal organ cultures by immunohistochemistry acetone fixed cryosections. Image caption: . Detection of viral antigen (A,B,C) and induction of apoptosis (E,F,G) in TOC-Ch after infection with Ch/H9N2. TOC-Ch were infected with 104 PFU of Ch/H9N2 in the third consecutive passage or with PBS as non-infected control. Cryosections of TOC were used for immunohistochemical staining for viral nucleoprotein (A,B,C). (A) Non-infected TOC-Ch at 8 hpi, (B) Ch/H9N2-infected TOC-Ch at 8 hpi, (C) Ch/H9N2-infected TOC-Ch at 24 hpi. Non-infected TOC-Ch were negative for viral antigen staining at 24 hpi. In situ TUNEL staining for apoptosis (D,E,F). (D) Non-infected TOC-Ch at 24 hpi (no difference to non-infected TOC-Ch at 8 hpi), (E) Ch/H9N2-infected TOC-Ch at 8 hpi, (F) Ch/H9N2-infected TOC-Ch at 24 hpi. Brown staining indicates the presence of viral antigen (A,B,C) or apoptotic cells (D,E,F). From: Petersen H, Matrosovich M, Pleschka S, Rautenschlein S (2012). Replication and Adaptive Mutations of Low Pathogenic Avian Influenza Viruses in Tracheal Organ Cultures of Different Avian Species. PLoS ONE 7(8): e42260 .