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 with a single-edge razor blade**. 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.
** Tissue samples sizes over a few tens of milligrams should be prechopped into pieces less than 1 mm in cross-section. If your sample is already harvested and frozen, do not thaw. This is especially important if you are isolating nucleic acids. Rather, Cryopulverize the sample. For information on this method see http://www.biospec.com/product/40/biopulverizer/.
Fill the screw-cap vial at least 1/2 full (1/2-3/4 is okay) 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. However, an accessory adapter ring will be required. Call for information)
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 head (the later being attached to the motor). Rotate the loaded vial holder ring to a position where the hole in the vial holder ring is aligned with the anti-rotation pin sticking out of the wiggle head. Slide the vial holder ring down the pin and seat it on the wiggle head. Next, align the large, black plastic hold-down cap and slide it down to contact the tops of the microtubes.
3) Screw on and firmly hand tighten the aluminum knob. To do this, the locking pin, which is part of the knob, must be in the raised position. A slight twist of the pin keeps it in the raised position. After tightening the aluminum knob turn the locking pin on the knob so it can engage with one of the holes in the black hold-down cap.
IMPORTANT! The locking pin is an important safety feature. Test that the pin has engaged into one of the ring of holes on the hold down cap. To do this, attempt to further tighten or slightly untighten the knob. Do not proceed if the cap does not lock. Raise up the pin on the aluminum knob and repeat the tightening, locking and testing process.
4) 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).
5) 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 can 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.)
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 helps trap anything should it break free.
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.