If A Sample Is Rich In Protein, E.G. Fish Flesh, Complete Digestion Will Not Be Achieved Using The Amount Of Proteinase K And Buffer Suggested In The Protocol. If A Sample Cannot Be Digested Completely Or Appears Very Viscous, Add More LYS Buffer And Repeat Incubation. Centrifuge The Sample At Full Speed For 5 Minutes To Remove Undigested Remains And Only Use The Supernatant In The Following Steps. In The Subsequent Preparations, A Lower Amount Of The Sample Should Be Used. A General Rule Of Thumb Is To Start With Half Of The Maximum Amount Of Sample Suggested. When There Is No Problem In Digesting The Sample Completely And Passing The Lysate Through The Column, Amount Of The Sample To Be Applied Can Be Increased Gradually In The Next Preparations.