Fig 3. Optimized labeling of pBM-MSCs for MRI.

(A) Endorem was incubated with pBM-MSCs at different concentrations (25 μg/ml, 50 μg/ml, 100 μg/ml and 200 μg/ml) Superparamagnetic iron oxide particle were detected by Prussian Blue-staining and observed by optical microscopy. (B) The Prussian Blue staining was spectrophotometrically quantified on pBM-MSCs. The cells were lysed with 0.1% Triton X-100 and the absorbance of the extracts was quantified at 700 nm.