Immuno-LCM allows retrieval of tissue from specific CP compartments. A) Evidence of histological purity. Immunofluorescence was performed using FITC-conjugated pan-cytokeratin antibody to highlight the CP epithelium (green), while immunohistochemistry using alkaline phosphatase detection with NBT/BCIP as substrate was carried-out to label the endothelium of CP stromal capillaries (dark brown). LCM was performed on a Pixcell IIe LCM unit. Images both BEFORE and AFTER LCM, as well as LCM retrieved tissue deposited on the cap, are shown to highlight selective retrieval of CP stromal capillary (top row) and CP choroidal epithelial tissues (bottom row). B) Evidence of purity by qrt-PCR. Levels of CD31, an endothelial marker, and Cytokeratin-8, an epithelial marker, were probed to determine the purity of the CP capillary and CP epithelial tissues, respectively, retrieved by LCM.