Operating Instructions for the Mini-BeadBeater-16

Preparation of Sample

Use 0.1 mm beads for bacteria, 0.5 mm beads for yeast, fungus, 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 chrome 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 see

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 latter 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 stainless steel knob.  To do this, the black locking pin, which is part of the stainless steel knob, must be in the lowered position.  A slight lift and twist action of the black locking pin keeps it either in the raised or lowered position.  As you screw on the stainless steel knob the pin 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 stainless knob stainless steelFirmly hand-tighten the aluminum knob until it is impossible to get additional "clicks".  But, do not use a tool to over-tighten the stainless steel knob.

          IMPORTANT! The locking pin is an important safety feature.  Do not proceed if you do not hear clicking sounds as you tighten the knob.  Remove the knob and visually test to see if the locking pin is in the down position.

4)  Operate the MBB-16 with the black plastic hood lowered over the chamber. This prevents the user from coming in contact with the shaker during operation and helps trap anything should it break free.  A magnetic sensor in the hood prevents the MBB-16 from running when the hood is raised.

5)  Set the timer. A typical setting time for cell disruption is 2-3 minutes. The timer automatically resets to its last run time.

          NOTE: Colliding beads generate heat. Typically, the sample temperature increases by about 10 deg C per minute of beadbeating.  If you are isolating heat-sensitive biomaterial, consider homogenizing for a shorter period, say 1 minute, then remove the vial holder and its vials and cool the vials in an ice-water mix for 1 minute. Cycle this beadbeating/cooling cycle for a total 'On' time of three minutes. No cooling is required for nucleic acid extraction providing cell disruption is done in commercial nucleic acid extraction media.

          The MBB-16 timer automatically resets to its last run time.

6)  Start the MBB-16 by pressing the start/stop button.   The timer automatically resets at the end of a run.

           NOTE: MBB-16s manufactured before April 2008 have a different timer mechanism.  Start the shaker by pressing the white button in the center of the timer dial.

7)  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 position). Unscrew the stainless steel knob, remove the black vial hold-down cap, and finally the vials in their vial holding ring. The vial holding ring can be conveniently placed on a provided blue vial ring holder (an upside-down tumbler).

8)  Remove the homogenate from the microvial with a micropipette.  Beads quickly settle to the bottom of the microvial.  Using a micropipette tip having an inlet diameter smaller than the beads, slowly withdraw the homogenate, leaving the beads behind.

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 helps trap anything should it break free.


The external spring (for pre-April 2008 MBB-16 units) or the external rubber O-ring on the MBB-16 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 tools nor opening the MBB enclosure.