Scientists in the United States say that they have found a way to make the lethal Ebola virus harmless in the laboratory.
They believe their discovery will help research into a vaccine or cure for the deadly virus.
Ebola first emerged in 1976 in the Sudan and Zaire; the virus which causes hemorrhagic fever kills anywhere from 50-90% of its human victims.
Ebola is currently handled in highly secure labs, and the researchers say by removing a single gene from the virus they have stopped it replicating.
They say this process genetically disarms the virus, making it safe for scientists to handle.
The researchers from the University of Wisconsin at Madison, say the need for the most stringent biosecurity levels for any laboratory working with Ebola means that very few research institutions have the capability to do this.
Biosecurity levels 4" (BSL4) are needed which requires researchers to wear biosafety suits with their own air supply and the air pressure in the room must be less than the pressure outside, so any leak would mean air flowing inwards rather than outwards.
Such measures say the team guarantees that anything more than small-scale studies of the virus are very difficult to arrange and research is limited to possibly as few as a dozen laboratories worldwide.
The researchers say if Ebola could be kept in a viable form but with the risk of infection removed, then conventional research laboratories might be able to study it.
The researchers believe the key is to remove one of Ebola's eight genes, called VP30, as without it, the virus cannot replicate within host cells by itself.
However, in order that virus could still replicate so it could be studied, they developed monkey kidney cells which contained the protein needed.
The researchers say because the cell was providing the protein, and not the virus itself, it could only replicate within those cells, and even if transferred into a human, would be harmless.