After this period, cells were fixed and used for the determination of alkaline phosphatase (ALP) activity and
von Kossa staining for the detection of mineralization.
Some of the histiocytes had basophilic intracellular MG bodies (Figure 1), which were round bodies of varying sizes that reacted positively with the periodic acid-Schiff and
von Kossa stains.
Calcium salts were stained after
von Kossa following published protocols [15].
The induced cells were stained with
von Kossa to confirm osteogenesis, safranin O to confirm chondrogenesis, and oil red O to confirm adipogenesis.
Differentiation into osteocytes was assessed by
von Kossa staining.
(c) DPCs were cultured in osteogenic induction medium for 14 days, and the mineralized nodule formation was assessed by
von Kossa staining (scale bar = 100 [micro]m).
After 4% PFA fixation and positive colonies were counted, mineralized bone nodule formation was assessed by double labeling for mineral (
von Kossa stain) and alkaline phosphate (ALP).
Sections measuring 5 pm width were obtained and stained using hematoxylin and eosin (HE), Gomori's trichrome or
Von Kossa stain to observe the tissue morphology.
von Kossa staining was performed to show the mineralization and calcium deposition of differentiated cells as a marker of osteogenic transformation.
The
von Kossa method for quantifying calcium crystal formation and deposition was performed as described previously (5).