FGF22(Fibroblast growth factor 22) is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. A proliferation assay was conducted to detect the bioactivity of recombinant human FGF22 using Balb/c 3T3 cells. Briefly, 3T3 cells were seeded into triplicate wells of 96-well plates at a density of 4,000 cells/well and allowed to attach overnight, then the medium was replaced with various concentrations of FGF22 diluted with serum-free standard DMEM. After incubated for 48h, cells were observed by inverted microscope and cell proliferation was measured by Cell Counting Kit-8(CCK-8). Briefly, 10 µl of CCK-8 solution was added to each well of the plate, then the absorbance at 450 nm was measured using a microplate reader after incubating the plate for 1-4 hours at 37°C. Proliferation of Balb/c 3T3 cells after incubation with FGF22 for 48h observed by inverted microscope was shown in Figure1. Cell viability was assessed by CCK-8(Cell Counting Kit-8 ) assay after incubation with recombinant FGF22 for 48h. The result was shown in Figure2. It was obvious that FGF22 significantly increased cell viability of 3T3 cells. The ED50 of recombinant human FGF22 is 187ng/ml.

Figure 2. The dose-effect curve of FGF22 on Balb/c 3T3 cells.