MicroMincer

The MicroMincer^tm is a compact, hand-operated screw press which macerates up to 0.3 grams of soft¹ fresh plant or animal tissue (e.g. muscle, liver, brain, epicotyl and pulpy leaf tissue) without sample loss, heat generation, foaming or aerosol problems.

The stainless steel MicroMincer utilizes disposable polypropylene liners. Thus, multiple samples can be quickly processed without the need to clean or the risk of contamination between samples.

The sample, without added buffer, is forced through a 250-micron stainless-steel sieve inside the liner.  The tissue emerges from the tip of the MicroMincer having a consistency of liver paté.

In the case of most plant tissues, the fibrous pulp is left behind on the sieve while clarified cell juices and intracellular products are extruded.  This resultant, undiluted extract can be deposited directly in microtubes for further analysis.

APPLICATIONS

• Microanalysis of cellular constituents.
• Direct sample extraction for PAGE and agar gel analysis.
• Preparation of viable single-cell suspensions from tissue^2a,2b

1.  Highly fibrous animal tissue containing collagen (e.g., skin, some tumors, cartilage) cannot pass through the sieve.
2a.  See  Singh NP (1998) A rapid method for the preparation of single-cell suspensions from solid tissues. Cytometry 31: 229-232.
2b.  Maceration of tissue samples with a MicroMincer reduces fresh tissue to very small tissue fragments while minimizing shear and sample heating.  The time to harvest single cells from a process of enzymatic tissue disaggregation is significantly shortened.  Furthermore, diffusion of nutrients and gases into the tissue during incubation with the enzymes are enhanced, thus optimizing cell viability.  (For an excellent review of Enzymatic Tissue Disaggregation see http://www.worthington-biochem.com/tissuedissociation/basic.html)

HOW IT WORKS

1. Put 100 mg to 500 mg of tissue into the barrel of the disposable plastic liner. (pre-chopping of firm tissue into pieces less than 1 mm in cross-section may be needed.  Pre-chopping soft tissue is usually not necessary).
2. Partially insert the threaded piston with a black rubber seal installed into the barrel of the plastic liner and slide this assembly into the cylinder of the MicroMincer.
3. Screw down the press. The tissue extract will exit from the pointed end of the liner.  Continue screwing down the press until all of the sample has been extracted. Too much pressure beyond this point will shear the plastic tip of the liner and force it out of the MicroMincer.  The plastic liner is a disposable item, so no harm is done.  With very small samples, some of the extract may remain inside the liner tip. This can be removed with a micropipette or small spatula.
4. Unscrew the press and remove the used liner and the piston seal.