After being dried the pieces of membrane that filtered the blood are examined for diatoms and pollen grains. ‘’’Colloidal Silica Gradient Centrifugation method’’’ can be used with liver and lung samples. The tissue collected is added to saline solution, centrifuged at a temperature of 12 degrees Celsius, and then added to distilled water to then be mounted on a slide and observed. ‘’’Dry Ash method’’’ can only be applied to a bone marrow sample. Five grams of marrow is taken from a victim to be placed in a nitric acid solution and then bunt in a furnace allowing the release of diatoms to then be analyzed.[7]