General Procedures:

  1. Chop or cut tissue into small pieces (approximately 1mm in length) using a safety razor blade or scissors.  If your sample is already prefrozen and too large to be easily drawn up into the tip of the probe, you may need to Cryopulverize the sample (see https://www.biospec.com/products/biopulverizer?taxon_id=28).
  2. Place tissue in homogenizing vessel containing 3 to 10 volumes of homogenizing medium.
  3. Lower the bottom one inch of the probe into tissue suspension, turn on the Tissue-Tearor, and operate for 5 seconds to 2 minutes using an up-and-down dabbing motion.  Do not immerse the probe more than one-half way into the homogenization solution.  Use lower speeds for subcellular particle preparation and its maximum motor speed for biochemical or macromolecule extractions. While the Tissue-Tearor does not heat up samples during homogenization, if desired the homogenizing vessel can be placed in an ice bath during homogenization.  The Tissue-Tearor can be stand-mounted using a tri-clamp and ring-stand.  This is a convenient configuration when processing numerous samples.
  4. To avoid splashing, turn off the Tissue-Tearor before withdrawing from the homogenizing vessel.
  5. Place the TT in the provided plastic stand when not being used so that liquids can drain out.  Do not place it on its side.


Cleaning of the Tissue-Tearor is important.  Many biological materials and extraction media are surprisingly corrosive, even if the probe is stainless steel.  If the biomaterial gets into the upper part of the probe and into the motor bearings, the motor bearing will be destroyed.  Between repetitive samples, the unit can be superficially cleaned by briefly operating the TT in a vessel containing water or detergent.  At the end of the day, unscrew the stainless steel stator (the outer part) and pull straight off the inner rotor, which is still attached to the motor.  [CAUTION, never turn on the Tissue-Tearor with the stator removed - it will bend the rotor].  Wash rotor and stator in detergent, rinse and dry the parts and reassemble the probe on the motor.  If necessary, both the entire probe (both stator and rotor) can be repeatedly removed from the motor unit and autoclaved.


The inert, fluorocarbon sleeve-bearing on the rotor shaft will need to be replaced from time to time.  This need is usually indicated by an observed increase in motor vibration and a noisy, buzzing sound during operation.  Spare fluorocarbon bearings have been included with the Tissue-Tearor along with the special wrench to remove the rotor from the motor's chuck.

If you replace the fluorocarbon bearing and the unit is still noisy then you may have a bent rotor, or the armature and bearing assembly is rusted.  Please call us for further information and spare part numbers.