Fig. 12. Select the best puromycin concentration A: sUMSCs(50×); B: After 1.5μg·mL-1 puromycin screening for 48h sUMSCs(50×); C: At the end of puromycin screening sUMSCs(50×) (Add puromycin to sUMSCs when the confluence was 70%-80%, and record the time and concentration of almost all cell death as the foundation for subsequent resistance screening. )