Colorimetric Calcium Assay

As an essential mineral for all living organisms, 99% of calcium is deposited in bones and teeth, while 1% found in extracellular fluid or within cells bound to proteins. Changed level of calcium in body fluid, such as serum, is found to be associated with many diseases such as hyperparathyroidism, neoplastic diseases, hypoparathyroidism, nephrosis and etc. ScienCell provides a simple and direct colorimetric measurement of calcium concentration in biological samples, utilizing the purple-red complex formed between calcium and ortho-cresolphthalein in alkaline medium. The optimized formulation eliminates the interference from magnesium and helps to release calcium bound to proteins. Intensity of the developed color (λ=570 nm) is proportional to the calcium concentration in the physiologically important range (0.3-20 mM).