Cryogenic Sample Storage: -80 °C vs Vapor-Phase Nitrogen

General reference information for researchers and lab staff, not medical advice and not a procedure. Follow your institution’s biosafety and cryogen-safety rules.

Short answer

Cryogenic sample storage keeps biological material at ultra-low temperature so it degrades slowly. The NCI Best Practices for Biospecimen Resources (2016 edition) says that when future uses are uncertain, tissues should be stored in the vapor phase of a liquid nitrogen freezer or frozen at -80 °C. Vapor phase is generally preferred over liquid phase.

Definition and scope

In practice, “cryo storage” and “cryogenic storage” are the same activity. Cryostorage is commonly conducted in liquid nitrogen or its vapour phase, and the NCI best practices cited below treat the vapour phase as the preferred tier. Many labs also store samples in -80 °C freezers, which sit in a warmer tier. This page covers the sample side: which tier, how samples are divided, and what gets recorded. For hardware, see cryogenic freezers and liquid nitrogen freezers.

How sample storage is run in practice

The NCI document reproduces College of American Pathologists (CAP) Biorepository Accreditation Program checklist items. Taken together they form a sample-side checklist:

• Aliquot for single use. Multiple small aliquots allow work on one specimen while minimizing freeze-thaw degradation of other stored samples (CAP BAP.01900). Freeze-thaw cycles may be deleterious to the macromolecules intended for analysis, so some aliquots should have a suitable single-use volume.
• Record the cooling rate. The rate at which samples are cooled to storage temperature can influence molecular degradation, and later freeze-thaw cycles can degrade molecular integrity further.
• Log temperature daily. Temperatures are recorded every day, seven days a week; automated or remote monitoring is acceptable if staff have immediate access, and an emergency response plan applies if ranges are exceeded. Excursions are tracked (BAP.02000).
• Log liquid nitrogen use. Daily usage and levels are monitored and documented for each storage container (BAP.08700).
• Map temperatures. The temperature difference between the bottom and top of a liquid nitrogen freezer should be measured and considered in planned analyses; regular mapping is recommended and required by accrediting agencies (BAP.08100). See the temperature mapping protocol.
• Plan back-up capacity. Keeping 10% back-up storage containers for each type of temperature-controlled unit would be considered best practice (BAP.08500).

Temperature tiers compared

Tier	What the sources say	Source
-80 °C freezer	One of two options for tissues when future uses are uncertain.	NCI 2016
Liquid nitrogen, vapor phase	Preferred over liquid phase: it provides temperatures low enough to stay below the glass transition temperature (Tg) and avoids hazards inherent in liquid-phase storage. The top of a liquid nitrogen freezer is consistently below -140 °C.	NCI 2016 (CAP BAP.08600)
Shipping on dry ice	-70 °C; dry ice is a hazardous substance for shipping.	NCI 2016
Shipping in a dry shipper	At or below -150 °C, using liquid nitrogen.	NCI 2016

The same NCI document also mentions -20 °C and -70 °C freezers in individual tissue studies; those are study-specific examples, not general recommendations. Related reading: ultra-low-temperature freezer maintenance and liquid nitrogen handling safety.

Frozen blood, proteins and other sample types

Frozen blood

For liquid biospecimens such as blood, NCI says consideration should be given to producing components such as plasma or serum, which should be separated before storage. It also notes that cryopreserving whole blood rather than fractions may be an efficient option for processing viable cells in large-scale studies. Which approach fits depends on the planned analysis.

Storage of proteins

The NCI document speaks to macromolecules in general: aliquot for single use and limit freeze-thaw cycles. It does not give a temperature for any particular protein, so protein-specific conditions should come from the protein’s own supplier documentation or the validated method. (The phrase “storage protein” in a biological sense, meaning seed or tissue reserve proteins, is a different topic.)

Viable cells

NCI notes that lower storage temperatures and a cryoprotectant such as dimethyl sulfoxide may be used to maintain viable cells for long periods. For cell-line practice see cryopreservation of cells and cryovials.

Where it matters for labs

Accrediting agencies require some of these records, so storage practice shows up in audits as well as in data quality. Inventory is part of the same system; see lab freezer inventory systems.

Common misunderstandings

• “Colder is the same everywhere in the tank.” Temperature differs between the bottom and top of a liquid nitrogen freezer, which is why mapping matters.
• “Thawing a sample once is harmless.” Freeze-thaw cycles may be deleterious to macromolecules; aliquoting exists to avoid repeated cycles on one stock.

FAQ

Are cryo storage and cryogenic storage the same thing?

Yes. Both refer to storing material at ultra-low temperature, typically in liquid nitrogen vapour or liquid below -150 °C, with -80 °C freezers as a warmer tier.

How should blood be stored frozen?

NCI advises separating plasma or serum before storage for most liquid-biospecimen uses, while whole-blood cryopreservation is an option for viable cells. The choice follows the planned analysis.

How are proteins stored?

In small single-use aliquots to limit freeze-thaw cycles; protein-specific temperatures come from supplier documentation or a validated method.

Is vapor phase or liquid phase better?

NCI, reproducing a CAP checklist note, says vapor phase is generally preferred because it keeps samples below Tg and avoids liquid-phase safety hazards.

Sources

• National Cancer Institute, Best Practices for Biospecimen Resources, 2016 edition (read 2026-11-08).