Western blot using Affinity Purified anti-Rif1 antibody shows detection of a band ~265 kDa corresponding to mouse R(arrowhead). Specific reactivity with this band is blocked when the antibody is pre-incubawith the immunizing peptide (data not shown).Approximately 25 µg of MEF whole cell lysawas separated by SDS-PAGE and transfeonto nitrocellulose. After blocking the membrane was probed with the primary antibody diluted to 1.0 µg/ml for 2 h at room temperature followed by washes and reactiowith a 1:10,000 dilution of IRDye(TM)800 conjugated Gt-a-Rabbit IgG [H&L] MX for 45 min at room temperatuIRDye(TM)800 fluorescence image was captured using the Odyssey(R) Infrared Imaging Systemdeveloped by LI-COR. IRDye is a trademark of LI-COR, Inc. Other detection systems will yield similar results.