Irises: A practical tool for image-based analysis of cellular DNA content.

The DNA content of nuclei is a valuable measure of cell cycle status. Irises is a software tool to facilitate systematic in situ determination of DNA content for cell cycle analysis at single-nucleus resolution within complex tissues. We demonstrate the utility of the tool with analysis of DNA content in germline nuclei of C. elegans. Compared with results obtained by manual analysis, we find the tool greatly facilitates analysis by improving speed at least 5-fold while maintaining accuracy. The source code and instruction manual (including installation for both Mac and PC) are provided.