Liquid Nitrogen
Liquid Nitrogen - Related Videos
06:42
A Multi-hole Cryovial Eliminates Freezing Artifacts when Muscle Tissues are Directly Immersed in Liquid Nitrogen
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Cited by 9 •
2017
This protocol describes a procedure to freeze muscle tissues by plunging them directly into liquid nitrogen. This protocol also highlights a new cryovial that can avoid the "blanket effect" of nitrogen gas when liquid nitrogen contacts the tissue surface of a specimen.
01:49
The Nitrogen Cycle
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2019
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
10:41
Carbon and Nitrogen Analysis of Environmental Samples
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2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University Elemental Analysis is a method used to determine elemental composition of a material. In environmental samples such as soils, scientists are particularly interested in the amounts of two ecologically important elements, nitrogen and carbon. Elemental analysis by the flash combustion technique works by oxidizing the sample with a catalyst through combustion in a high-temperature chamber. The products of combustion are...
07:49
On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes
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Cited by 14 •
2016
A method combining comprehensive two-dimensional gas chromatography with nitrogen chemiluminescence detection has been developed and applied to on-line analysis of nitrogen containing compounds in a complex hydrocarbon matrix.
09:05
Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials
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Cited by 9 •
2015
Nitrogen is an effective supercritical fluid for extraction or drying processes due to its small molecular size, high density in the near-liquid supercritical regime, and chemical inertness. We present a supercritical nitrogen drying protocol for the purification treatment of reactive, porous materials.
FAQs
Liquid nitrogen preserves biological material primarily by removing heat so quickly that molecular motion decreases sharply. As the liquid vaporizes, it carries absorbed heat away from the sample, lowering the activity of processes that could alter it. This rapid thermal control is valuable when researchers need to retain the original state of cells, tissues, embryos, or microbial cultures.
At approximately −196 °C, the low temperature suppresses enzymatic reactions, metabolism, and chemical degradation. These processes can otherwise change biological molecules or alter sample characteristics over time. By slowing them, cryogenic storage helps maintain specimen integrity and supports long-term preservation, making later biological measurements more comparable with the original material.
When liquid nitrogen vaporizes, it produces expanding nitrogen gas that can create a cold, inert atmosphere. This environmental effect complements direct cooling by surrounding the sample with conditions that are both cold and chemically inert. In biological laboratory processes, that combination can help researchers control not only sample temperature but also the atmosphere in which the process occurs.
Applications include cells, embryos, tissues, and microbial cultures. The common purpose is to place these materials under conditions that slow metabolism and other degradative processes, allowing their properties to remain more stable during long-term storage. This broad range makes the approach useful across studies involving intact biological specimens as well as cultured or microbial systems.
Researchers can freeze biological samples before extraction and molecular analysis. The rapid cooling limits enzymatic activity, metabolism, and chemical degradation, helping preserve the molecular state present before freezing. Once preserved, the sample can support analyses connected with genetics, physiology, or disease. In this role, freezing is a preparation step that protects interpretive value rather than an endpoint.
Preserving specimen integrity improves the consistency of material used across experiments. When cells, embryos, tissues, or microbial cultures experience less metabolic and chemical change during storage, researchers can compare results with greater confidence that differences reflect the biology under study rather than progressive sample degradation. This supports reproducible work in genetics, physiology, and disease research.