Integrated direct loop mediated isothermal amplification microdevice for detection of bacteria in human whole blood without DNA extraction

Abstract

We have developed a direct loop mediated isothermal amplification (D-LAMP) microdevice incorporated with an immunochromatographic strip (ICS) for detecting bacteria in human whole blood. The fabrication and operation of the microdevice could be effectively simplified by utilizing a slidabe reaction chamber instead of using the microvalves and pumps for the fluid control. The D-LAMP technology does not require the cell lysis and purification step for amplifying DNA. Intact bacterial cells spiked in the whole blood was directly used as a template. Staphylococcus aureus (S. aureus, ATCC 12600) and Escherichia coli W (E. coli, ATCC 9637) in the whole blood were detected in the ICS without the sample pretreatment step within 70 min.