Fig. 3.

Kinetics of STAT1 activation after treatment of human tumor cell lines with IFNα and IFNγ. (A) A representative Western blot of protein extracts from M14 cultivated in the presence or absence of 250U/ml of IFNα for the indicated periods. Illustration is derived from high resolution scanning of films exposed for 30 min. Only control samples extracted from cells after 6 h of culture in the absence of IFNα are included in the picture because there was no significant difference (p > 0.5) in the intensity of chemiluminescent bands between samples after 15 min, 3 h, or 6 h of culture. (B) A representative Western blot of protein extracts from M14 cultivated in the presence or absence of 250U/ml of IFNγ for the indicated periods. Illustration is derived from high resolution scanning of films exposed for 30 min. Only control samples extracted from cells after 6 h of culture in absence of IFNγ are included in the picture because there was no significant difference (p > 0.5) in the intensity of chemiluminescent bands between samples after 15 min or 6 h of culture.