DLD-1 is one of two colorectal adenocarcinoma cell lines which were isolated by D.L. Dexter and associates during a period from 1977-1979. The cells have been used in the study of polar solvents on cell characteristics. The four cell lines: DLD-1, HCT-15, HCT-8 and HRT-18 have been shown to have a common genetic origin. DLD-1 can express carcinoembryonic antigen (CEA) 0.5 ng/106 cells/10 days and colon antigen 3. These cells are weakly positive for keratins and vimentin. The cells are positive for keratin by immunoperoxidase staining.