Sonication, high intensity emission of ultrasounds creating cavitation, is ideal for DNA, RNA and chromatin shearing as well as for cell lysis and tissue homogenization. In addition, sonication can be used for many other biological but also for chemical, pharmaceutical & industrial applications (>> Applications overview).

Diagenode's Bioruptor® uses ACT (Adaptive Cavitation Technology) to create focused mechanical stress to shear biological samples in a temperature controlled environment. The ultrasound waves, generated by an ultrasound transducer which is located below the sonication bath, pass through the sample, expanding and contracting the liquid. During expansion, negative pressures pull the molecules away from one another and form a cavitation bubble. The bubble continues to absorb energy until it can no longer sustain itself and then implodes, producing intense focused shearing forces which disperses or breaks biomolecules (Figure 1). The fragmentation of biological samples occurs due to this mechanical stress.

Figure 1: The entire volume of water present in the sonication bath is exposed to ultrasound, allowing all the samples in the sonication bath to be efficiently sonicated in parallel

Features and benefits of the Bioruptor®

• Fast & simple
• No contamination between samples
• Gentle processing
• Reproducible
• Temperature controlled
• Multiplexing capability of up to 12 samples per run

>> Learn more about specifications of the different Bioruptor® models

As the most cited sonication device (> 700 publications), the Bioruptor® has acquired an unmatched reputation in the scientific community.

Diagenode's Bioruptor® simultaneously shears multiple samples in sealed tubes of 0.1 ml to 50 ml capacity quickly and accurately, providing optimal fragment lengths. The Bioruptor® exhibits a laboratory friendly format as it is easily programmable and capable of processing multiple sample tubes, with parallel processing of 3 - 12 samples. The instrument uses standard tubes and is able to sonicate different sample volumes to achieve different fragment size ranges. The closed tube format prevents the sample from cross-contamination and aerosol formation.

The Bioruptor® utilizes a sonication bath-based rotor. The walls of the sonication bath reflect the ultrasound waves in a random but reproducible pattern. The samples in the tube holder are rotated through the ultrasound field to expose each sample to the same level and intensity of energy to ensure shearing consistency. A unique cooling system providing isothermal processing and the gentle ultrasound preserve and retain the integrity of biological samples and ensure high sample recovery.

What are the effects of ultrasound on biological samples?
High powered ultrasound waves can produce gaseous cavitation in liquids. Cavitation is the formation of small bubbles of dissolved gases or vapors due to the alteration of pressure in liquids. These bubbles are capable of resonance vibration and produce vigorous eddying or microstreaming. This mechanical stress has multiple effects on biological samples including; effective chromatin shearing, DNA & RNA shearing, cell lysis and tissue homogenization. When using a probe sonicator, the microstreaming phenomenon is limited to the vicinity of the probe which can generate high amounts of heat and release metal fragments. In contrast, the Bioruptor® sonication bath is equally exposed to ultrasound energy allowing for the dissipation of heat and providing uniform absorption of energy.

How does it work?
Ultrasonic waves generated by the transducer produce longitudinal vibrations (alternating compression and rarefactions) in the water bath (see figure below). These pressure fluctuations create millions of microscopic bubbles (cavities) caused by the negative pressures generated by the rarefaction stage. As the cavities are exposed to the positive pressures, produced by the compression stage, they oscillate and expand to an unstable size (up to 100 microns diameter). Finally the cavities will implode generating pressure extremes and temperatures at the implosion sites. In addition, shock waves and eddies radiate outwardly from the site of cavity collapse. The localized hot spots that last for microseconds can have temperatures of ~5,000ºC, pressures of ~500 atmospheres as well as heating and cooling rates >109 K/s. The cumulative energy generated by this cavitation phenomenon is extremely high and produces intense shearing forces (Figure 1).

Figure 1: Presentation of bubble size in function of time during sonication process.