Calcium glucoheptonate

By lysing cells, releasing RNA, and removing impurities such as proteins and DNA, high-purity RNA products are finally obtained. The commonly used traditional method is the guanidine isothiocyanate/phenol/chloroform method (Trizol), which is suitable for a variety of animal materials including animal tissues, microorganisms, cultured cells, etc., and most plant materials.

Mesenchymal stromal/stem cells can be induced toward an osteoblast-like lineage in vitro by culture in osteogenic medium containing dexamethasone, ascorbic acid or ascorbate-2-phosphate, and β-glycerophosphate; the differentiation process is commonly evaluated by alkaline phosphatase activity, osteogenic marker expression, collagenous matrix formation, and calcium-rich matrix mineralization. The main readouts are alkaline phosphatase activity as an early osteogenic marker and Alizarin Red S staining as a calcium-deposit readout for mineralized extracellular matrix; Alizarin Red S can be inspected microscopically or extracted and measured colorimetrically at 405 nm.

The following protocol uses the MTT colorimetric assay as a classic literature-established method for assessing cell viability/metabolic activity in cultured mammalian cells. MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] is reduced by metabolically active cells to a colored formazan product; the amount of formazan is quantified spectrophotometrically and provides an indirect measure of metabolically active viable cells. Importantly, MTT reduction reflects cellular oxidoreductase/metabolic activity rather than an absolute direct count of living cells, so changes in cellular metabolism can alter the signal independently of cell number.