Medicine:Straw (cryogenic storage)
A cryopreservation straw is a small storage device used for the cryogenic storage of liquid samples, often in a biobank or other collection of samples. Their most common application is for storage of sperm for in-vitro fertilization.
Ideally such straws should be made of a material that is chemically inert, biocompatible and have physical characteristics that make them resistant to ultra-low temperatures and pressures created by their storage conditions, resulting in the expansion of liquids and liquid nitrogen.[1]
Use
Once the sample has been introduced into the straw, both extremities are thermally sealed using a specific device, usually supplied by the manufacturer of the consumable.[2]
The straws are then stored within triangular or square visotubes, which in turn fit into cylindrical or square containers known as goblets. These are then organized into a matrix of the same within an ultra-low temperature freezer or nitrogen tank.
Characteristics
- specifically designed for storing biological materials at temperatures as low as -190 °C;
- stable when submitted to sudden low temperatures (snap freezing), when held at low temperatures for long periods of time (years ) or when taken through several freeze-thaw cycles; and
- as leak proof as possible even at the lowest cryogenic temperatures.[2]
References
- Embryo and Sperm Freezing – Cryopreservation – Arizona
- Nonequilibrium cryopreservation of rabbit embryos using a modified (sealed) open pulled straw procedure | Animal Reproductive Biology and Embryology
External links
- Safety of vitrification. Embryo News. June 28, 2013.
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