Expression of subtype-specific markers by the intraductally generated DCIS-like lesions. Intraductal lesions were generated by injection of SUM-225 (a, d, g), DCIS.COM (b, e, h), and FSK-H7 (c, f, i). Six weeks after injection, fat pads containing intraductal lesions were removed and fixed, followed by paraffin embedding by using standard histological techniques. Paraffin sections were subjected to immunofluorescence studies with antibodies against human CK-19 (a-c), Her-2 (d-f), and CK-5 (g-i). Primary antibodies were conjugated to secondary antibodies, Alexa-594 against mouse anti-human CK-5 and CK-19 (red), and Alexa-488 against rabbit anti-human Her-2 antibody (green).