The TissuePress is a simple screw press, designed to efficiently macerate or mechanically disaggregate 5 to 50 grams of fresh or reconstituted soft plant or animal tissue. By 'soft' we mean nonfibrous tissue like brain, liver, muscle, potato, callus, etc. Dried or tough tissues like wood chips, leaves or skin will not pass through the stainless steel screen.
The TissuePress is used as a mincing step for isolation of single cells or the extraction of intracellular components such as nuclei and mitochondria. Unlike other tissue dispersion/blending devices, no added water or buffer is required in its operation. See Narendra P Singh, et. al. for preparation of viable single cell suspensions*.
*DNA double-stranded breaks in mouse kidney cells with age, Narendra P Singh et. al., Biogerontology 2, 261-270 (2001)
Disaggregation of tissue for primary culture or staining: A common method to isolate single cells from tissue samples involves enzymatic digestion of the extracellular connective matrix. The first step in the process is to increase access of added digestive enzymes to the tissue by chopping the tissue into pieces with a scissors or sharp blades. In a significant improvement, much smaller tissue pieces can be obtained by maceration of tissue samples with the TissuePress. This greatly speeds up the rate of enzymatic disaggregation. As an important added benefit, the TissuePress reduces the tissue to pieces so small that diffusion of nutrients and gasses are not limiting during the prolonged incubation with digestive enzymes. (An brief review of Enzymatic Disaggregation is found at http://www.worthington-biochem.com/tissuedissociation/default.html.)
Brief Operating Instructions:
Partially retract the piston of the TissuePress to make room for the tissue. Unscrew the brown 'cap' with its array of 2 mm holes and place the tissue sample into the cavity of the Tissue press. If the tissue is partially fibrous or covered with membrane, first trim off the tough or fatty parts. Fibrous tissue can interfere with the passage of the soft tissue through the press.
Generally, the 2 mm array of holes molded into the press cap is used. If you choose to use the 500 micron stainless steel wire sieve, place it on the press cylinder before screwing on the press cap. Screw down the piston to extrude the tissue. The dispersed tissue will exit the press having a paste-like texture. Depending on the amount of connective or fibrous tissue present in the sample the yield of dispersed tissue will vary from 20-95%.