Although mass spectrometry has been used to determine the chemical composition of materials for decades it had rarely been used to identify viruses especially in complex environmental samples.
Researchers at the Johns Hopkins Bloomberg School of Public Health successfully separated, purified and concentrated a norovirus surrogate from a clinical sample within a few hours using proteomic mass spectrometry.
Human norovirus causes gastrointestinal illness, commonly on cruise ships. Because of their mass spectrometric method they have immense potential as a tool for biodefens. The results of the study is published in the April 2006 edition of Applied and Environmental Microbiology.
In mass spectrometry is essentially a laser turns a sample into ionized particles, which are then accelerated in a vacuum toward a detector. The time lapsed prior to their being detected on a detector helps researchers determine the mass of the particles. By targeting characteristic particles, or peptides, belonging to the viral coat protein, the virus can be correctly identified by matching the results to entries in genetic databases.
In the Hopkins study, a stool sample treated with non-infectious virus-like particles, structurally similar to the norovirus was analyzed using mass spectrometry. Norovirus capsid protein was noted down to levels commonly found in clinical specimens from sick individuals.
This process is especially significant because of the fact that the norovirus cannot be cultured outside the human body.
This could be a significant step towards the use of mass spectrometry as an environmental surveillance tool in detecting pathogenic human viruses in complex environmental samples.