Real-time quantification of soluble tartrate-resistant acid phosphatase as a measure of osteoclastogenesis

Differentiation of osteoclasts from their macrophage precursors can be assessed via multiple methods including microscopy, gene expression analysis, and protein immunoblotting, but these methods can be expensive or labor intensive and subject to variation in approach and interpretation. We have developed a low-cost kinetic assay for the quantification of Tartrate Resistant Acid Phosphatase (TRAP), which is secreted by osteoclasts in increasing amounts as they differentiate. This assay demonstrates reliable reproducibility and provides sensitive, quantified data that accurately represents altered levels of osteoclastogenesis due to variations in Receptor Activator of Nuclear Factor κB (RANK) signaling and the presence of known osteoclast inhibitors. The assay is cost-effective, scalable and readily adoptable by labs conducting osteoclast biology research.