The location and translocation of proteins, signaling molecules, and other small molecules inside cells regulate cell growth, differentiation and many other cellular functions. Separating cytosol and particulate fractions is an important step in studying subcellular localization of cellular components. However, traditional methods usually take hours to separate cytosol from particulates, so that some cellular components especially small molecules and metabolites are getting diffused or redistributed during the separation procedure. The new Cytosol/Particulate Rapid Separation Kit physically separate cytosol from particulate compatments rapidly through an oil layer and thus the two fractions would not contact or diffuse to each other. Using the method, contaminations can be avoided even for small molecules. Subcellular localization and analyses of factors interested can be performed accurately.