Automated Microfluidic Device Simultaneously Detects HIV RNA and Antibodies

Diagnostic laboratories now have available a fully automated molecular testing device that simultaneously detects host anti-HIV antibodies and viral RNA in a single specimen of saliva or blood.

In developing the system, Rheonix Inc. (Ithaca, NY, USA) optimized a commercially available HIV serologic assay to run within a microfluidic device into which was also incorporated an isothermal LAMP assay to detect the presence of viral RNA. LAMP (Loop-mediated isothermal AMPlification) is highly regarded for its rapidity, sensitivity, and ability to amplify both DNA and RNA.

The finalized system consisted of a disposable injection molded and film-laminated microfluidic CARD (Chemistry and Reagent Device) disposable device and a portable, software controlled instrument, which together automatically performed all steps of both assays without any user intervention after the initial loading of samples and reagents.

The microfluidic CARD cartridge had multiple microchannels, valves, pumps, and reservoirs, which performed the immunoassay, isolated viral RNA for detection by magnetic bead based purification, and Reverse Transcriptase loop-mediated isothermal amplification (RT-LAMP). The microfluidic system was able to detect host anti-HIV antibodies and viral RNA simultaneously in up to four blood or saliva samples.

The system was shown to detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection of HIV RNA. It also addressed the well-known "seroconversion window" during early HIV infection when antibodies are not yet detectable and viral loads are at their highest.

“Our technology meets the needs of settings with limited resources. The assays are rapid, sensitive, specific, easy to perform, and inexpensive,” said Dr. Greg Galvin, CEO of Rheonix. “This combined HIV screening and confirmatory test will have a significant commercial and social impact that we’re excited to see materialize.”

The assay device was described in detail in the January 31, 2016, online edition of the Journal of AIDS & Clinical Research.

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Rheonix Inc.