A virologist from Göttingen has developed an easy to carry
suitcase-lab that will enable medics to
run full-fledged genetic tests for a
variety of viruses. Until now, this was all but unthinkable.
RPA-Mini-laboratory,
developed by the German Primate Center in Göttingen (Foto: DPZ)
The RPA mini-lab includes everything to identify eight
different viruses.
When a patient shows up at the doctor's office with fever,
the first assumption in countries with colder climates usually is:
"another case of the flu." In tropical regions, however, doctors are
likely to offer "malaria" as a first ad hoc diagnosis. But this first
assumption can be dangerously misleading. The fever could also have been
triggered by a much more dangerous infection, such as the Dengue, Marburg or
Chikungunya virus, or even - in the worst scenario - by Ebola.
Ahmed Abd el Wahed wants to give local clinics fast and
reliable diagnostics
It is critical that medics obtain clarity about the origin
of symptoms as early as possible. With this in mind, virologist Ahmed Abd El
Wahed thought it would be good to have a small, mobile laboratory. He pursued
his idea together with a colleague, Frank Torsten Hufert, at the University of
Göttingen, where Abd El Wahed was researching at the time. Initially, his aim was
to offer doctors in Mecca a device they could use to test pilgrims of the Hajj
for the MERS-Corona-virus.
Back then, nobody in Saudi Arabia was interested in his
suitcase. However, Abd El Wahed now hopes that the invention could be of use in
Africa: a mobile laboratory, which fits into a suitcase, can run full-fledged
genetic analyses on a number of different viruses. Moreover, the tests reach a
degree of reliability that was so far unthinkable outside well-equipped
classical medical laboratories. So the mini-lab is well suited for use in
clinics in the Ebola-affected regions of West-Africa. And it is already in use
there.
An Ebola rapid test - similar to a pregnancy test - has been
on the market since January. However, the suitcase-lab is not supposed to
replace that option.
But, while every physician can carry the rapid test at all
times and identify an Ebola-infection with a high degree of certainty, the
method is not fool-proof. There is still the possibility that an
Ebola-infection remains undetected. Therefore, in case of suspicion,
blood-tests will always have to be taken and sent to a proper laboratory for
DNA-testing.
And this is where the suitcase lab comes into play: Abd El
Wahed's brain child can perform in-depth DNA-analysis right on the spot - a
great advantage in underdeveloped countries where bad roads can make
transportation difficult. Furthermore, the lab can test blood samples for as
many as eight different viruses, including all three known varieties of Ebola -
something the instant test can't do.
Multiplying genetic information
To conduct DNA-analyses, researchers need to multiply
specific sections of genetic information. Traditionally, this is done using a
method called polymerase chain reaction (PCR).
Polymerase chain
reaction machine at the Fraunhofer Institute in Schmallenberg (Foto: Fabian
Schmidt)
A PCR goes through numerous heating and cooling cycles
This method is used when forensic investigators take genetic
fingerprints, or when medics conduct a paternity test or food controllers want
to find out the origins of meat.
But PCR requires a complex laboratory with extensive
equipment. Test tubes with the genetic material must be heated and cooled
repeatedly: first to 96 degrees, then to 50-60 degrees and again to 72 degrees
Celsius. This procedure must be repeated numerous times, which can take hours.
Also, some ingredients must be continuously cooled to minus 20 degrees Celsius
during transport.
Breakthrough with a new method
This changed in 2006 when a team of researchers under
biochemists Olaf Piepenburg and Niall Armes invented a new DNA multiplication
procedure called recombinase polymerase amplification (RPA).
RPA multiplies the required genetic information of the
viruses faster than PCR - within ten to fifteen minutes. In addition, RPA works
at a continuous temperature of 37 degrees, which means no cooling is needed in
the process or transport of ingredients.
In June 2014, Abd El Wahed, who works at the German Primate
Center in Göttingen, had his suitcase ready for use. Piepenburg and Armes
contributed necessary equipment and ingredients, which they have now converted
into a start-up enterprise.
DNA-diagram from a
PCR machine at the Fraunhofer Institute in Schmallenberg (Foto: Fabian Schmidt)
This is how PCR finds DNA-identities - through peaks in a
diagram
Abd El Wahed's former boss, the virologist Manfred Weidmann
- now teaching at the University of Sterling - contributed the specific RPA
test for the Ebola virus.
The device receives its electric power from a solar panel.
At the moment, it is being tested with cooperation partners of theInstitut
Pasteur in Dakar/Senegal and with the Institute of Public Health in Guinea.
Besides hospitals, Abd El Wahed also thinks the suitcase
could be useful at airports. "If someone arrives at an airport with
symptoms, you can find out what he has in 15 Minutes," Abd El Wahed
boasts. The estimated costs for the mini-lab is currently around 5000 euros.
Each test costs about four euros.
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