Validation of the REverSe TRanscrIptase Chain Termination assay for measuring tenofovir diphosphate in dried blood spots from a clinical pharmacokinetic trial.

Background: Tenofovir diphosphate concentration in red blood cells is an objective measure of long-term oral pre-exposure prophylaxis (PrEP) or antiretroviral therapy (ART) adherence. However, current methods for measuring tenofovir diphosphate are equipment and capital intensive, limiting widespread adoption.

Objectives: Low cost, rapid diagnostics for measuring tenofovir diphosphate may drive clinical adoption of routine drug level measurement as a tool for adherence monitoring of tenofovir disoproxil fumarate-based PrEP or ART.

Democratizing Access to Microfluidics: Rapid Prototyping of Open Microchannels with Low-Cost LCD 3D Printers.

Microfluidics offer user-friendly liquid handling for a range of biochemical applications. 3D printing microfluidics is rapid and cost-effective compared to conventional cleanroom fabrication. Typically, microfluidics are 3D printed using digital light projection (DLP) stereolithography (SLA), but many models in use are expensive (≥$10,000 USD), limiting widespread use.

REverSe TRanscrIptase chain termination (RESTRICT) for selective measurement of nucleotide analogs used in HIV care and prevention.

Sufficient drug concentrations are required for efficacy of antiretroviral drugs used in HIV care and prevention. Measurement of nucleotide analogs, included in most HIV medication regimens, enables monitoring of short- and long-term adherence and the risk of treatment failure. The REverSe TRanscrIptase Chain Termination (RESTRICT) assay rapidly infers the concentration of intracellular nucleotide analogs based on the inhibition of DNA synthesis by HIV reverse transcriptase enzyme.