Viscera should be preserved if the cause of death is suspected. All of the following does not require preservatives, EXCEPT:
Preservatives are not necessary if, Viscera can be analyzed within 24 hours If sample can be kept in a refrigerator or ice box Bone, hair, nails Lung for detecting inhaled poisons Ref: The Essentials of Forensic Medicine and Toxicology by Dr. K. S. Narayan Reddy, 27th edition, Page 111.
Nail
Hair
Bone
Brain