BioSqueezer Cryogenic Tissue Clamp

BioSqueezer Instructions

The BioSqueezer is used to quickly freeze animal and human tissue samples.  Tissue is compressed into a thin disc under a stainless steel clamp head that is pre-cooled in liquid nitrogen or dry ice.  Soft tissue freezing occurs in a few milliseconds, thus capturing a snapshot of metabolic events in the cells.  The resultant hard frozen tissue disc is easily fragmented or ground without thawing for subsequent extraction of labile nucleic acids, proteins, and intracellular metabolite products. 

Operation of the BioSqeezer:  A small beaker, styrofoam cup or similiar vessel is placed on the BioSqueezer's platform and the metal clamp is lowered.  Liquid N2 is slowly and carefully poured into the vessel until the boiling action of the liqN2 subsides.  This cooling process takes about a minute and, once cooled to liquid N2 temperature, the stainless or aluminum metal clamp head will remain cold for several minutes.  The vessel is removed and the sample, by itself or already placed in a poly-bag, is positioned on the platform and the knob is quickly lowered and clamped.  This clamping step must be done rapidly or the tissue sample will freeze uncompressed.

The optimal clamp setting of the BioSqueezer will vary depending on the softness and size of the tissue sample.  Try adjusting the BioSqeezer using "practice" tissue.  The clamping force and  degree of squeezing on the tissue is selected by adjusting the height of the stainless steel clamp head with its wing nut, black plastic nut, and stainless steel hex bolt.

While still hard frozen, the thin wafer of tissue can be manually fragmented inside it's poly bag.  Presenting a tissue sample in small fragments is ideal for quick homogenization, extraction, or storage in stabilizing solutions such as RNA later or other excipients.