Fig.1. Analysis of MC1-CFTR clones. (A) β-galactosidase staining with X-gal for the indicated clones. MC1 (CHO-MC1 cells) represents the negative control. (B) FISH analysis of the clones indicated in each panel with a CFTR probe. Chromosomes were counterstained with propidium iodide and the probe was revealed with avidin-FITC. The arrow points to the minichromosome.