Mini-BeadBeater-16
Instructions for the Mini-BeadBeater-16
Preparation of Sample
Use 0.1 mm beads for bacteria, 0.5 mm beads for yeast, fungi and tissue culture cells and 1.0 mm or 2.5 mm beads for fresh plant and animal tissue. If you have solid tissue, pre-chop it into pieces having approximate 1mm cross-section with a single-edge razor blade or fragment the tissue at liquid nitrogen temperatures with a BioPulverizer (available from BioSpec Products). Up to 400 mg (wet wt) of biomaterial can be disrupted per ml of extraction media. In most applications, beads made of glass or zirconia-silica give excellent results. In special cases (grinding dry leaf material, wet grinding soaked seeds, disrupting skin or cartilage) beads made of denser material such as zirconia or steel may be required. Click here for additional guidelines on selecting bead media.
Fill the 2 ml screw-cap microtube one-half to two-thirds full with beads. Then add extraction media and cells, being sure to fill the microtube almost to the top. Exclude as much air from the microtube as possible. Use screw-cap microtubes with integral o-ring seals in order to eliminate aerosol formation during the homogenization. Be sure there are no beads on the threads of the microtubes when screwing down the cap.
( CAUTION - snap-top microtubes release aerosol. Nevertheless, it is possible to use snap-top microtubes in the MBB-16. An accessory adapter ring will be required.)
Operating the Mini-BeadBeater
1) Load 1 to 16 microtubes into the clear, vial holder ring holder. Distribute them symmetrically as you would do with a centrifuge. If using less than 4 sample vials, insert "blank" vials so that at least four vials are in the holder.
2) Place the loaded vial holder ring on the aluminum wiggle mechanism (the later being attached to the motor). IMPORTANT! Rotate the vial holder ring to a position where one of the four holes in the vial holder ring is aligned with the anti-rotation pin sticking out of the wiggle mechanism. Slide the vial holder down the pin and seat it on the wiggle mechanism. Align the pin and the center bolt of the wiggle mechanism with the holes in the large, black plastic hold-down cap and slide it down to contact the tops of the microtube caps. Finally, screw on and hand tighten the black knob. Tighten it firmly.
3) Set the timer. A typical setting for cell disruption is 2-3 minutes. (Note: If you are working with heat-sensitive material, consider homogenizing for a shorter period, say 1 minute, then remove the vial holder with its vials and cooling the vials in ice-water for 1 minute. Cycle thus, for a total "On" time of three minutes. No cooling is needed for nucleic acid extraction providing you are doing cell disruption in nucleic acid extraction media).
4) Start the machine by pressing the start/stop button (for pre-April 2008 MBB-16 units, press the white button in the center of the timer dial). The timer resets itself automatically at the end of the run.
(CAUTION for pre-April 2008 units - While the MBB-16 is running, changing the Timer setting will damage the timer. If you must change the time setting while the MBB-16 is running, press and hold down the white start button while changing the position of the timer dial.)
Safety Concerns
Operate the MBB-16 with the black plastic hood over the chamber. This prevents the user from coming in contact with the shaker during operation and will help trap anything should it break free.
Maintenance
The sealed bearing inside the wiggle mechanism get hot during operation. If many samples need to be processed, the lifetime of the bearing will be increased by allowing it to cool down between runs.
The external spring (for pre-April 2008 MBB-16 units) or the O-ring will need to be replaced from time to time. See BioSpec for a repair kit should the spring or O-ring break.