Copy number of EBV-DNA in EBV-associated gastric carcinoma.

Estimation of cancer cell ratio (CCR) was calculated for the adjustment of qPCR data. An EBV-associated gastric carcinoma (EBVaGC) case (A, hematoxylin and eosin staining) was immunostained with the monoclonal antibody AE1/AE3 (B). Using immunohistochemistry images, all the nuclei (blue) were automatically counted by the Tissue Studio software in the whole and cytokeratin immunostained regions (C). The CCR in EBVaGC cases (n = 43) distributes 4.1%–49% with a median of 22% (D). EBV-CN was obtained from qPCR data divided by the CCR (qPCR/CCR). Copy numbers of EBV-DNA per genome (EBV-CN) in EBVaGC cases (n = 43) are in the range between 1.2 and 185 with a median of 9.9 (E). A–C: Scale bar represents 100 μm. B: Inset is negative control, in which staining was performed without primary antibody. D, E: The bars represent the median and quartiles.