Detection of human DNA in the air

Large quantities of human cells and DNA fragments are continually released into the air and this constitutes a significant proportion of indoor dust. This study explored the feasibility of aerosol DNA as a source of information to aid human identification in criminal cases. Air samples were collected using the AirPrep™ ACD220 electret filter air sampler from indoor environments. Dust samples were collected in parallel from surfaces in the same areas. A new method to extract human DNA from the air filters was developed. DNA profiles were evaluated in relation to the use and time of occupancy of the room from where samples were collected. This study showed that human DNA can be collected from air in sufficient amounts to yield full STR genotypes, suggesting the potential use of aerosol DNA as a novel investigative tool for forensic applications.