In general, crimp vials are not intended for low temperature use. The rubber septa may become brittle at low temperatures, thus compromising the air-tight seal. If it becomes necessary to transport samples in crimp vials at low temperatures, the following guidelines must be followed:
- Crimp vials consist of 3 pieces: 1) a glass vial, 2) a rubber septum, and 3) an aluminum cap. The sample is introduced into the glass vial in an inert atmosphere glove box, the mouth of the vial is closed with the septum and the assembly is covered with the aluminum cap. A hand crimping tool is used to make a compression seal.
- If the sample needs to be kept at low temperatures it must be cooled, transported and stored at dry ice temperatures. If desired, better anaerobicity can be attained by covering the crimpled aluminum top with a layer of wax or a saran sheet, which is snugged down around the neck of the crimp-vial with a tightly wound rubber band or wire wrap.
- If lower temperatures are needed the sample must be cooled without submerging in LN and transported in a dry LN2 shipper. When the shipper arrives at its destination, the samples should be transferred to a low temperature freezer (-80 °C). Note, crimp vials should NEVER be submersed in LN2. This allows LN2 to leak into the vial. When the vial is removed from LN2 and allowed to warm, the influxed LN2 will flash evaporate and produce an extremely rapid pressure-jump. An explosion hazard is created.
- Whenever possible, plastic cryo-vials (with LN2 outlet holes in the vial) should be used as an alternative to crimp vials. Capped, stoppered, or removable seal containers should never be submersed in LN2.
- Safety glasses and gloves must be worn whenever handling cryogenics. In addition, a face shield must be used when handling crimp vials that have been stored at low temperature
