Zika Update: Engineers Develop New Portable Zika Test Costing Only $2
Engineers from the University of Pennsylvania have developed a new rapid, low-cost diagnostic tool that is capable of testing Zika virus.
The new testing device, explained in a proof-concept paper published in the journal Analytical Chemistry, will only cost about $2 and can be easily brought anywhere. It is only about the size of a soda can and will not require electricity or technical expertise to run. The user would only provide a saliva sample and the dye in the device will change its color to blue when the genetic assay the presence of the virus.
At present, Zika virus can only be detected by tests looking for antibodies that response to the virus or through tests that look for RNA sequences from the virus itself. However, the tests looking for responsive antibodies are insufficient because they may provide a false negative from people who are infected with the virus but haven't yet produced antibodies or a false positive from people who have antibodies for a different disease similar enough to trigger the tests.
On the other hand, tests that are looking for RNA sequence, known as reverse transcriptase polymerase chain reaction, or RT-PCR, may avoid having false positive or false negative. However, this kind of test requires the viral sequence of the patient's sample to be amplified in multiple precise temperature changes in order to achieve detectable levels.
With the new Zika virus test kit, the engineers used an alternative technique known as reverse transcription loop-mediated isothermal amplification, or RT-LAMP, instead of the RT-PCR. By doing so, the engineers were able to bypass the delicate laboratory work required in TR-PCR.
The researchers first identified highly conserved region of the ZIka virus genome that are different from other known pathogen. Then, they designed appropriate primers to recognize the identified sequence.
According to a press release, the new kit will only take about 40 minutes to run the test in detecting the presence of the ZIka virus through the patient's saliva. The kit is put inside a thermos bottle to keep the sample at the necessary temperature. The bottle and the kit was then covered with a 3-D printed lid to hold all the components in place.