A Flow-Through Ultrasonic Lysis Module for the Disruption of Bacterial Spores

Abstract

An automated, flow-through ultrasonic lysis module that is capable of disrupting bacterial spores to increase the DNA available for biodetection is described. The system uses a flow-through chamber that allows for direct injection of the sample without the need for a chemical or enzymatic pretreatment step to disrupt the spore coat before lysis. Lysis of Bacillus subtilis spores, a benign simulant of Bacillus anthracis, is achieved by flowing the sample through a tube whose axis is parallel to the faces of two transducers that deliver 10 W cm−2 to the surface of the tube at 1.4-MHz frequency. Increases in amplifiable DNA were assessed by real-time PCR analysis that showed at least a 25-fold increase in amplifiable DNA after ultrasonic treatment with glass beads, compared with controls with no ultrasonic power applied. The ultrasonic system and integrated fluidics are designed as a module that could be incorporated into multistep, automated sample treatment and detection systems for pathogens.

Acoustic micro-vortexing of fluids, particles and cells in disposable microfluidic chips

“…These methods are impressive and efficient, but require purpose-made microchips or integrated transducers with specific geometrical features, which limit their applicability. Furthermore, cell lysis has previously been performed in miniature chambers by various techniques (Nan et al 2014 ) including acoustic methods, e.g., lysis of bacterial spores by either sonication at 40 kHz in a cartridge combined with a filter (Taylor et al 2001 ), or by sonication at 1.4 MHz with a dual-transducer system submerged in a water tank (Warner et al 2009 ). However, both these systems have rather complex physical structure that makes them difficult to integrate in microfluidics.…”

Extraction of nucleic acids from bacterial spores using bead‐based mechanical lysis on a plastic chip

“…To extract DNA (and other molecules of interest, such as RNA or proteins), cells of a particular sample must be subjected to a lysis process during which the cell envelope is disrupted and intracellular content released in the surrounding medium. There are a number of methods using chemical or physical principles that can be used to this end, many of which are being investigated for automation and integration in lab-on-a-chip devices [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Chemical methods rely on the presence of lysing agents, such as organic solvents, detergents or enzymes that degrade the surrounding layers of a cell.…”

“…A common approach relies on exposure to low-or high-frequency ultrasound for shock waves dissipating in the liquid medium cause cavitation and breakdown of the cellular structures. Sonication methods can be readily applied to a broad range of sample volumes, effectively promoting microfluidic integration of sample preparation protocols [6][7][8]. On-chip cell disruption has further been shown in conjunction with thermal [9], electrochemical [10] and hydrodynamic (shear-force) methods [11,12].…”

“…The rotating bar is connected to an electromotor (5) located further below the stage. The setup can accommodate up to four chips(6), each of which contains a lysis chamber(7) and a metal disk(8) at its interior. The chips are kept in designated sections using a double-sided adhesive film(9).…”

Ultrasonication on a microfluidic chip to lyse single and multiple Pseudo‐nitzschia for marine biotoxin analysis

“…Therefore, we propose to use mechanical forces via ultrasonic waves to rupture Pseudo-nitzschia for DA extraction. Previous work has demonstrated the versatility of ultrasonicbased methods for cell lysis, which appears to be a promising approach for automated fluidic biodetection systems [17,18].…”