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 less than 1 mm in cross-section 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.
** 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 click here.
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 black locking pin, which is part of the aluminum knob, must be in the lowered position. A slight lifting/twist action of the black locking pin keeps it either in the raised or lowered position. As you tightening the aluminum knob the pin it will engage with a ring of metal teeth on the black hold-down cap. You will hear clicking sounds as you continue to hand tighten the knob aluminum. Firmly hand tighten the aluminum knob until it is impossible to get an additional “click”. But, do not use a tool to tighten the aluminum knob.
IMPORTANT! The locking pin is an important safety feature. Do not proceed if you do not hear clicking sounds as you tighten down the hold-down cap. Remove the cap and visually test to see if the locking pin is in the down position.
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). The timer automatially resets to it last run time.
5) Start the machine by pressing the start/stop button. The timer automatically resets itself at the end of a run. For pre-April 2008 MBB-16 units having a different timer mechanism, press the white button in the center of the timer dial. Also for pre-April 2008 units: While the MBB-16 is running, changing the Timer setting can damage the timer).
6) To remove the vials and vial holding ring, first raise the locking pin in the up position (a slight lift and turn of the locking pin knob will keep it in the raised positon). Unscrew the aluminum knob, remove the black vial hold down cap and, finally the vials in their vial holding ring. The vial holding ring can be conviently be placed on a provided blue vial ring holder (alias: up-side-down tumbler).
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 external spring (for pre-April 2008 MBB-16 units) or the external O-ring will need to be replaced from time to time. See BioSpec for a repair kit should the spring or O-ring break. The change out is a simple 5 minute task and does not require opening the MBB.