Analysis for Bik/Nbk expression in transfected H9 T-lymphoma cells. (A) RT-PCR and Southern blot: The exogenous mRNA transcript was detected by RT-PCR with primers designed to vector specific forward sequence and Bik/Nbk specific reverse sequence, yielding a 292-bp fragment. DNA was electrophoresed, Southern blotted and hybridized by the use of a third, radiolabeled oligonucleotide specific for the 5′ terminus of Bik/Nbk. Positive and negative controls were pCIN.Nbk plasmid (lane 1) and water (lane 2). Lane 3, H9 3D8 control transfected cells; lane 4, clone no. 2; lane 5, clone no. 7; lane 6, clone no. 10; lane 7, clone no. 13; lane 8, clone no. 16. (B) Western blot analysis for Bik/Nbk expression: Protein extracts from SW480 colon carcinoma cells (lane 1), H9 3D8 control cells (lane 2) or Bik/Nbk transfected clones no. 2 (lanes 3 and 4) and 10 (lane 5) were separated by SDS-polyacrylamide gel electrophoresis and Western blot analysis with a goat antiserum against Bik/Nbk. Yeast expressed Bik/Nbk Gal4-Nbk fusion protein served as a positive control (lane 6). Bands were visualized by means of ECL.