Fig. 6. Co-immunoprecipitation of 6ß4 and D6.1A. (A) Lysates of Progressor cells were precipitated with B5.5, anti-ß4, anti-3, anti-ß1 and D6.1. After gel separation and transfer, membranes were stained with D6.1. (B) Lysates of biotinylated Progressor cells were immunoprecipitated with C4.4 (anti-C4.4A), D5.7 (anti-EpCAM), Ox50 (anti-panCD44), anti-CD9, anti-ß4, anti-6, B5.5, D6.1 and A8.10 (non-binding antibody). After gel separation and transfer, membranes were stained with streptavidin, D6.1 and anti-CD9. A large amount of D6.1A was recovered in D6.1-, anti-CD9-, anti-6 and anti-3 precipitates. D6.1A was also precipitated by B5.5, anti-ß4 and anti-ß1. Small amounts of D6.1A were recovered in precipitates with Ox50 and D5.7. No D6.1A was recovered in C4.4 and A8.10 precipitates. CD9 was only recovered in anti-CD9 and D6.1 precipitates.