Figure 4. Western blot analysis of MAPK in human gingival fibroblast. Cells were plated in 24-well plates at an initial density of 30,000 cells/well and allowed to attach overnight in MEM containing 10% (v/v) FBS. Subsequently, cells were rinsed twice with PBS, serum-starved for 24 hrs, treated as indicated, and then subjected to lysis on the plates. Antibodies were used for the detection of MAPK and phosphorylated MAPK as described in MATERIALS & METHODS. (A) Effects of bFGF and HIP on the phosphorylation of Erk-1 (p44) and Erk-2 (p42). (B) We verified equal loading by re-probing with antibody recognizing both phosphorylated and non-phosphorylated forms of p44 and p42.