Figure 2.

Interaction between pituitary conditioned media and BMP-4 analyzed by surface plasmon resonance. BMP-4 was immobilized at intermediate density (4600 RU) on a flow cell of a CM5 sensorchip, and DMEM-BSA or $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$10$}\right.$-diluted DMEM-BSA or medium conditioned for 6 h (CM basal 6 h) or for 48 h (CM basal 48 h) diluted $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$10$}\right.$ were then injected for 180 s over the chip at 30 μl/min, and dissociation was studied for 120 s (plain lines). The sensorgrams are subtracted with the nonspecific interaction values obtained on an activated-deactivated control flow cell. Spotted lines represent aliquots of media concentrated over PEG as described under “Results” and $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$50$}\right.$-diluted before injection. The figure shows one representative experiment. Similar results were obtained with CM provided by six independent pituitary cultures.