Scientists from PATH and the US Centers for Disease Control will collaborate under a three-year grant from the National Institutes of Health to further develop and test a non-instrumented DNA amplification kit for diagnosing diseases in resource-poor areas of the world, according to recently published grant information.
Under the grant, administered by the National Institute of Biomedical Imaging and Bioengineering and worth $693,000 in its first year, PATH researchers led by Paul LaBarre propose to work with CDC scientists to combine exothermic chemical heating with loop-mediated isothermal amplification to create a nucleic acid testing kit that does not require electricity and can be used at the point of care.
As reported by PCR Insider in June, LaBarre and colleagues previously demonstrated proof of concept for their "non-instrumented nucleic acid," or NINA, platform in a research paper published in May in PLoS One (PCR Insider, 6/9/11).
The NINA kit prototype described in that paper used an exothermic reaction of CaO and water combined with an engineered phase change material to maintain a steady temperature for conducting isothermal nucleic acid amplification.
More specifically, the group demonstrated the use of this heating method with the LAMP technique to amplify DNA from the malaria-causing parasite Plasmodium falciparum, and obtained results comparable to those obtained with commercial PCR devices such as PerkinElmer's GeneAmp 9600 and Qiagen's ESE-Quant Tube Scanner.
Now the group seeks to take its assay one step further by working with CDC under the NIBIB grant to streamline the design of the kit and test it on another pathogen that plagues low-resource areas of the world: HIV-1.
According to the grant's abstract, the CDC "has developed a novel combination of lysis buffer, [LAMP] reaction, and fluorescently labeled primer to enable a simplified, extraction-free and lysis-free workflow."
These innovations, the abstract adds, "can be combined with a simple two-chamber, high-containment reaction tube prefilled with lyophilized LAMP mixture to create the first electricity-free, instrument-free, and easy-to-use, low-cost [nucleic acid amplification testing] kit."
Specific aims of the research grant include specifying and optimizing the properties of the electricity-free incubator active materials using the existing incubator prototype; adapting CDC's assay innovations to a LAMP-based HIV-1 assay; establishing dry reagent formulations; and defining the sample type to be tested.
Additional aims include designing and fabricating optimized versions of the isothermal incubator and reaction containment tube; and finally, validating the HIV-1 assay kit in the laboratory, the grant's abstract states.
The researchers also said that they envision eventually customizing and validating their optimized test kit for specific strains of infectious diseases such as HIV, tuberculosis, and malaria.
LaBarre previously noted that the group was aiming to develop a test kit that costs approximately $1.50, with the isothermal incubator component costing less than $0.50. However, this did not factor in any costs associated with the LAMP assay, the rights of which are owned by Japan'e Eiken Chemical.
The group has also said that it was collaborating with researchers at other institutions to assess the NINA technology with other isothermal methods, such as helicase-dependent amplification and nucleic acid sequence-based amplification.