 The sample is mixed with formalin, rinsed and centrifuged three times with distilled water.Then the pelletis removed from the test tube and added with 8ml of Soluene-350, incubated at 50 degrees Celsius for 2 hours, centrifuged again, and finally mounted on a slide.The ‘’’Enzymatic method’’’ is used for tissue samples and because of the use of enzyme chemicals it is considered an environmentally safe method and has a smaller percentage of damaging the diatoms collected than that of the acid digestion method.