SSEA-5 and L1CAM immunoreactivity in human tumor cell lines. A variety of human tumor cell lines were immunostained with either SSEA-5 or L1CAM using diaminobenzidine reaction so that immunopositive cells could be counted in groups of 100. (a) SSEA-5 and L1CAM immunoreactivity in human tumor cells. L1CAM (yellow bars) are plotted against the left -axis; SSEA-5 (blue bars) are plotted against the right -axis. Capan-1 displayed the greatest number of SSEA-5+ cells, while U87MG demonstrated the highest numbers of L1CAM+ cells. For all bars not visible, the number of positive cells was less than 1%. (b) Examples of fluorescent immunoreactivity: HT-29 cells display both SSEA-5 and L1CAM immunofluorescence, with some colocalization. LNCaP cells have low levels of L1CAM immunofluorescence and no detectable SSEA-5 immunofluorescence. Microscopic fields of T98G cells are immunonegative for both L1CAM and SSEA-5.