Alizarin Red S

Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
1. Preparation of Alizarin Red S^[1]
1.1 Prepare a 2% aqueous solution of Alizarin Red S sodium.
1.2 Use a pH meter to add ammonium hydroxide dropwise while stirring to adjust the pH to 4.2.
1.3 Filter the solution through a 0.45 μm microfilter and store in an amber bottle.
1.4 Refilter the solution through a 0.22 μm microfilter immediately before use.
2. Alizarin Red S detection of osteoblast differentiation^[2]
2.1 Osteogenic differentiation induction: MC3T3-E1 cells are seeded in well plates and are cultured in α-MEM (without ascorbic acid) supplemented with 10% fetal bovine serum. Osteogenic differentiation is induced by osteogenic medium (OSM) containing ascorbic acid (50 μg/mL) and β-glycerophosphate (10 mM).
2.2 Staining: MC3T3-E1 cells are washed with 1×PBS, fixed with 70% ethanol at room temperature for 10 min, rinsed with distilled water, and then stained with Alizarin Red S for 10 min to detect calcium deposition in the matrix.
2.3 Data analysis: The area of the red region is positively proportional to the degree of osteogenic differentiation.
3. Alizarin Red S Screening test for calcium compounds in synovial fluid^[1]
3.1 Synovial fluid preparation: Aspirate the synovial fluid into a disposable syringe and transfer the fluid to a clean test tube containing sodium heparin anticoagulant.
3.2 Staining: Aspirate a drop of synovial fluid from the bottom of the test tube, place it on a clean slide, mix it with a drop of 2% Alizarin Red S, and cover it with a coverslip.
3.3 Within three minutes of mixing, observe it under an ordinary light microscope and grade the degree of orange-red staining observed in each high-power field. The area of ??the red area is proportional to the content of calcium compounds.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.