Fig. 5. The antibodies against the 65 kDa (A) or the 110 kDa protein (B) inhibit splicing in vitro. Splicing reactions containing different amounts of the protein A-purified anti-65 kDa or anti-110 kDa antibody (anti-C110) (lanes 7–11), or corresponding IgGs from pre-immune serum (lanes 2–6), were incubated for 60 min and analysed on a 14% denaturing polyacrylamide gel. The amount of added antibody is stated above each lane. Lane 1 shows the pre-mRNA added to each splicing reaction. Pre-mRNA, splicing intermediates and products are indicated schematically.