Fig. 3: Assay optimization for POC applications.

a NA extraction protocol. Cells are lysed by proteinase K (Pro K) to release NAs. Subsequently, Pro K is heat-deactivated (95 °C), and the CreDiT reaction is initiated. b The lysis time and Pro K concentration ([Pro K]) were optimized to maximize the NA extraction yield. Samples containing Ca Ski cells (2.5 × 10⁴ cells/mL) were analyzed for HPV16. (Left panel) The extraction yields reached a plateau (red arrow) within 15-min of lysis. HPV16 signals from 20-min lysis were used for normalization. (Right panel) The extraction yield was maximal (blue arrow) at [Pro K] = 0.5 mg/mL and comparable to that of a spin column (gold standard). Data were displayed as mean ± s.d. from technical triplicates. c Extracted NAs were PCR-amplified for the HPV16 gene. Gel electrophoresis showed comparable bands between the CreDiT and the spin-column extraction methods. bp, base pairs. d Both extraction methods (CreDiT, spin column) yielded statistically identical results (unpaired, two-sided t-test) in analytical assays. Data were displayed as mean ± s.d. from technical quadruplicates. e CreDiT reagents were lyophilized and stored under ambient conditions. The lyophilized reagents demonstrated consistent activity for at least two weeks. Ca Ski cells (2.5 × 10⁴ cells/mL) were analyzed for HPV16. Data were displayed as mean ± s.d. from technical triplicates. a.u. arbitrary unit. Source data are provided as a Source Data file.