- 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 BioPulverizer.).
- Place tissue in homogenizing vessel containing 3 to 10 volumes of homogenizing medium.
- 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 the maximum motor speed for biochemical or macromolecule extractions. 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 convenient when processing numerous samples.
- To avoid splashing, turn off the Tissue-Tearor before withdrawing from the homogenizing vessel.
- Place the TT in the plastic stand provided 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, the lower 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). This exposes the rotor for thorough cleaning. [CAUTION, never turn on the Tissue-Tearor with the stator removed - it will bend the rotor]. Wash in detergent, dry the parts and reassemble the stator. If necessary, both the entire probe (both stator and rotor) can be removed from the motor unit and autoclaved.
The inert, fluorocarbon sleeve-bearing on the rotor shaft should be replaced from time to time. This is usually indicated by an observed increase in vibration and a noisy, buzzing sound during operation. Spare bearings have been included with the Tissue-Tearor along with the special wrench.
If you have replaced 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.