Rapid detection of bacterial cell from whole blood: Integration of DNA sample preparation into single micro-PCR chip

A novel bacterial cell detection method from blood samples has been developed for molecular diagnostics. Functional integration of DNA sample preparation into polymerase chain reaction (PCR) chip enabled detection of pathogenic bacterial cells in a single microchip. Surface-modified micropillars possessing affinity for bacterial cells were fabricated inside a PCR chip, and reaction conditions were optimized to render the microchip with high surface-to-volume ratio PCR-compatible. After bacterial cells were captured on the micropillars from whole blood and PCR inhibitors were washed out, PCR mixture was injected to allow real-time amplification of DNA extracted from the isolated cells. Cell enrichment effect produced by volume reduction from large initial sample to small micro-PCR chip chamber led to increased detection sensitivity. Moreover, the developed method from sample preparation to detection of bacterial cells from whole blood took less than 1 h. These results demonstrated that the surface-modified pillar-packed microchip would be a practical approach for integration into Lab-On-a-Chip (LOC) to enable point-of-care genetic analysis.