Evaluation of Tasso T20 to collect dried blood for the quantification of HIV-1 RNA.

Tasso T20 (T20) is a finger stick-free, self-sampling device capable of at-home blood sample collection. We optimized HIV-1 RNA elution from T20, evaluated its analytical performance, compared its performance to Whatman dried blood spots (DBS), and assessed HIV-1 RNA stability. We used mock viral samples to optimize HIV-1 RNA elution using viral concentrations 10,000 and 3000 copies/mL. Limit of detection (LOD) and limit of quantification (LOQ) were determined, and linearity and reproducibility were verified. Analytical agreement between T20 and DBS was assessed using eight concentrations, from 100,000 to 1000 copies/mL. T20 HIV-1 RNA stability was assessed over time. All samples were tested using the m2000 RealTime HIV-1 DBS assay. The optimized elution conditions selected were 30 min of sonication followed by 30 min of incubation at 55 °C. The 95 % LOD and LOQ were determined to be 3.56 and 3.70 log10 copies/mL, respectively. Good linearity was observed with a strong correlation (R2=0.98) and excellent reproducibility. Analytical agreement analysis demonstrated a mean difference of -0.36 log10 copies/mL (SD ± 0.21 log10 copies/mL). ANOVA indicated all samples remained stable (p value=0.33, F=1.22). The Tasso T20 is capable of quantifying HIV-1 viral loads, with results comparable to DBS.