Calcium assay kit

The ADSCs (from passage 4) were plated at a density of 10 × 10⁴ cells/well in 24-well plates containing an osteogenic induction medium for 21 days, and were divided into four groups as described in section 2.6. The exposure time duration for EMF exposed groups were 30 min per day for 21 days. Every 4 days, cultured cells were rinsed twice with PBS and trypsinized with Trypsin-EDTA. Subsequently, the suspension was collected to the 2 ml tube and treated with ultrasonication, and the supernatant was used for calcium determination according to the manufacturer’s instruction contained in calcium assay kit (Sigma, USA). Absorbance of samples was read at 570 nm after the addition of reagents. The total calcium was calculated from standard solutions prepared in parallel, and expressed as μg/well [29 (link)].

For the calcium assay, LNCaP cells were plated at 5 × 10⁴ cells per well in a 24-well CellBIND plate containing phenol red-free RPMI with 10% fetal bovine serum (FBS). Twenty-four hours later, cells were treated with TP and 1 mg/mL HX109. After 1 and 5 min, cells were washed with PBS and lysed with PBS containing 0.5% Triton X. The calcium levels of the cell lysates were measured using a calcium assay kit (Sigma-Aldrich, St. Louis, MO, USA) according to the manufacturer’s protocol.