The CryogenicTissueGrinder is a high speed blade mill that grinds 0.5-10 grams of plant, animal and human tissue with high water content to a fine powder in the presence of dry ice. The tissue becomes brittle at solid CO2 temperatures. A sample hit with a hammer (or in the case of the CTG111, a spinning blade) fragments into tiny pieces in a matter of seconds.
Cat. No. CTG111, 120 volts
Our Price : $0.00
Unique to the process, tissue freezing and fragmentation occur in seconds and no heat is generated during grinding. Nucleic acids, proteins and other biochemicals in the cell are preserved unaltered by the grinding process. If desired, the powdered tissue can be separated from the powdered dry-ice by lyophilization under vacuum or, more simply, by storing the mixture overnight in a deep freeze where the dry ice will sublime away. The size of the frozen, powdered tissue fragments speed up extraction with reagents or devices specifically designed to disrupt cells and optimizes non-refrigerated preservation of tissue with 'RNAlater' or other like expedients.
Note that this method works best with highly hydrated tissue. Drier tissues and materials such as wood, hair, feathers, bone and some skin and seeds may not cryogrind well with the CTG111. With those tougher tissues consider using devices which exploit the related process of cryopulverization.
Operating the CTG111
Dry ice (available from some local grocery stores) equal to 1 to 5 times the volume of the tissue is placed in the stainless steel cup of the grinder. Pre-powdering the dry ice for a second before adding tissue is recommended, especially with very soft tissue. With the prefrozen tissue added, the grinder is operated at maximum speed for 5-10 seconds.Tapping the sides of the grinding chamber during operation is sometimes helpful.
In a special application for microorganism suspensions, a thick, "paste-like" suspension of yeast or bacteria is extruded from a syringe onto pre-powdered dry ice to form frozen 'yeast spaghetti'. Grinding time is longer when cell disuption is the objective rather than tissue powdering. The time required for optimal cell disruption should be determined empirically by doing a time study.
Another method of lysing yeast at low temperature uses liq N2 to prepare small, hard frozen yeast pellets. After most of the liq N2 has evaporated, the frozen yeast pellets are powdered in the still very cold grinder. A detailed protocol authored by Jacqueline Hendries is available.
- Removable grinding chamber is stainless steel and dishwasher and autoclave safe
- Hands-free operation
- Built-in adjustable timer
- Compact size, L: 5 in, H: 9 in, W: 5 in
- 120 volts, 60 Hz, 210 watts