Western blot using Cd97 polyclonal antibody (Cat # PAB10186) shows detection of bands corresponding to free Fc-Cd97- (5EGF) (lower arrowhead) and Fc-Cd97- (5EGF) present as a complex (upper arrowhead) in lysates from COS cells. The left lane contains lysate from cells transfected with control DNA. The right lane contains lysate from COS cells expressing Fc-Cd97- (5EGF). No staining was noted from bone marrow lysates taken from Cd97 knockout mice. The identity of the band at ~65 KDa appearing in all lanes is not known. The formation of the Cd97 complex is currently under investigation. Approximately 10 uL of lysate was used in each lane. A 1:1,000 dilution of the primary antibody was used. The image was processed using a 10-sec exposure. Personal Communication. Yvona Ward. NIH, NCI, CCR, Bethesda, MD.