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

↑ Website of Cryo Bio System - manufacturer of straw storage systems www.cryobiosystem.com
↑ ^2.0 ^2.1 TUBAFROST Work Package 2: Development of storage system(s) for frozen tissue (technical aspects). (Deliverable 2.2 February 2004)