Citric Acid is an acidic compound from citrus fruits; as a starting point in the Krebs cycle, citrate is a key intermediate in metabolism. Citric acid is one of a series of compounds responsible for the physiological oxidation of fats, carbohydrates, and proteins to carbon dioxide and water. It has been used to prepare citrate buffer for antigen retrieval of tissue samples. The citrate solution is designed to break protein cross-links, thus unmasking antigens and epitopes in formalin-fixed and paraffin embedded tissue sections, and resulting in enhanced staining intensity of antibodies. Citrate has anticoagulant activity; as a calcium chelator, it forms complexes that disrupt the tendency of blood to clot. May be used to adjust pH and as a sequestering agent for the removal of trace metals. A useful buffer component for antigen and epitope unmasking
Soluble in water (59.2 g/100 ml) at 20 °C, ethanol, ether, and water (84.0 g/100 ml) at 100 °C. Soluble in water, ethanol and ether. Partially soluble in methanol, diethyl ether. Insoluble in n-octanol.
H2406382
