simple protocol for extracting diatoms from lung tissues of suspected drowning cases within 3h first practical application conventional acid digestion of tissues for analyzing diatoms obtained from suspected drowning cases is timeconsuming laborious and potentially dangerous we propose a new protocol for solubilizing lung tissue using only qiagen proteinase k qiagen buffer atl and 5n hydrochloric acid that can accelerate and simplify diatom extraction from suspected drowning cases the lower lobe of the right lung 1g inner region and the upper lobe of the left lung 1g peripheral region of ten immersed victims were digested in 15ml conical centrifuge tubes containing 9ml of buffer atl and 1ml of 20mgml proteinase k solution at 56c for 1560min the digest was washed with ultrapure water and then heated at 70c for 15min in 5n hydrochloric acid the acid residue was washed with ultrapure water followed by ethanol the identification of 6023000 valves in 20 lung samples from the ten victims suggested that they had aspirated water before death the proposed digestive protocol required only a lowspeed centrifuge and a block incubator or water bath and diatoms could usually be extracted from lung samples within about 3h informative results of lung diatom tests were very helpful to confirm drowning as a cause of death therefore the proposed protocol can be useful as a simple minimal test to support or challenge a diagnosis of death by drowning when characteristic autopsy findings of drowning are obvious and the probability of drowning is very high when characteristic autopsy findings of drowning are absent and the probability of drowning is very low and when conventional diatom testing is not performed due to logistic personnel or budgetary limitations