Centre for High-Throughput Phenogenomics

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Critical Point Dryer

Critical point dryer
Tousimis Samdri®-795 Critical Point Dryer

Tousimis Samdri®-795 Critical Point Dryer

Critical Point Drying is a sample preparation step that is needed for the complete removal of water from the sample without the damaging effects of surface tension.

The forces resulting from surface tensions are enormous. For example, to pull a DNA molecule (2 nm in diameter) out of water (which has a surface tension of 72 x 103 Nm-1), the total forces acting on the DNA thread can be calculated to be 1.47 x 108 Nm-2, which is 1.5 tons cm-2!

Critical point drying reduces the exerted surface tension on the specimen to zero by utilizing an occurrence known as the continuity of state for which there is no apparent difference between the liquid and gas state of a medium i.e. when the surface tension between this interface is zero. This occurs at a specific temperature and pressure with resulting density, and is known as the Critical Point. This condition of zero surface tension can be used to dry biological specimens, avoiding the damaging effects of surface tension. The Tousimis Samdri®-795 is a semi-automatic critical point dryer with a chamber diameter of 3.2 cm and depth of 3.2 cm that is capable of accommodating samples of various sizes with the accessories provided.

Key features of the Tousimis Samdri®-795 Critical Point Dryer

  • Liquid carbon dioxide transition fluid
  • Solid-state circuitry and simple push-button operation, as well as presets and internal controls, allow for precise and reproducible results
  • Accessories: small holder for 12 samples, coverslip holder, up to 10, 16-22 mm in diameter, Teflon tissue baskets


For more information about the capabilities and use of this machine, please send an e-mail.

Booking Calendar

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