Rapid cell lysis and DNA capture in a lysis microreactor

In clinical diagnostics, the detection and identification of bacterial organisms based on the analysis of their nucleic acids require cell lysis and DNA extraction from clinical samples. A lysis microreactor (LMR) has been developed to perform these tasks with high efficiency and in processing times of approximately 5–10 min. In this paper we report on (1) the kinetics of lysis, (2) the efficiency of DNA capture onto a strip that is inserted into the reactor and (3) application to the detection of Mycobacterium tuberculosis from clinical sputum samples. The LMR has a capacity of 2 ml and it is fitted with an impeller and temperature control. A polystyrene strip, inserted into the LMR at the start of the lysis process, captures the lysed ssDNA. Following a brief overview of the kinetics of lysis, the computational fluid dynamics results of the LMR are shown and a model of the DNA capture is presented. The application to clinical samples and controls demonstrates that this is a promising technology for fast turn-around times and sensitive diagnostics.

► Cell lysis kinetics is defined by three parameters that have been previously determined.
► Probability to be captured by the inserted strip depends on initial position.
► All DNA molecules can potentially be captured in the rotor wake.
► The technology has been applied to the diagnosis of M. tuberculosis.
► Turn-around times are short: 5 min lysis; 18–24 min PCR and ∼1 min for wash steps.