Dry Ice Freezing
Dry Ice Freezing - Related Videos
08:55
Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival
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Cited by 22 •
2013
Freeze-drying is often an easy and convenient way to obtain dry products of viable bacterial cells. An issue of the process is cell survival. We detail here a procedure to investigate how cell survival during freeze-drying is influenced by the properties of the formulation used.
06:57
Rapid High Throughput Amylose Determination in Freeze Dried Potato Tuber Samples
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Cited by 22 •
2013
This protocol describes a high through put colorimetric method that relies on the formation of a complex between iodine and chains of glucose molecules in starch. Iodine forms complexes with both amylose and long chains within amylopectin. After the addition of iodine to a starch sample, the maximum absorption of amylose and amylopectin occurs at 620 and 550 nm, respectively. The amylose/amylopectin ratio can be estimated from the ratio of the 620 and 550 nm absorbance values and comparing them...
10:16
Point-of-care CRISPR-based Diagnostics with Premixed and Freeze-dried Reagents
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Cited by 9 •
2024
Here, we present the step-by-step preparation of premixed, lyophilized recombinase-based isothermal amplification and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based reactions, which can be used for the detection of nucleic acid biomarkers of infectious disease pathogens or other genetic markers of interest.
12:00
Extraction and Purification of Polyphenols from Freeze-dried Berry Powder for the Treatment of Vascular Smooth Muscle Cells In Vitro
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Cited by 9 •
2017
This work details a step-by-step method to prepare polyphenol-rich extracts from freeze-dried berry powder. In addition, it provides a thorough description of how to use these polyphenol-rich extracts in cell culture in the presence of the peptide hormone angiotensin II (Ang II) using Vascular Smooth Muscle Cells (VSMCs).
11:17
Fundamental Technical Elements of Freeze-fracture/Freeze-etch in Biological Electron Microscopy
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Cited by 6 •
2014
Basic techniques and refinements of freeze-fracture processing of biological specimens and nanomaterials for examination by transmission electron microscopy are described. This technique is a preferred method for revealing ultrastructural features and specializations of biological membranes and for obtaining ultrastructural level dimensional and spatial data in materials sciences and nanotechnology products.
FAQs
The key mechanism is heat removal during sublimation. Solid carbon dioxide changes directly into gas, absorbing heat from nearby biological material rather than first producing a liquid phase. Because this transition occurs while dry ice remains near −78.5°C at atmospheric pressure, it can create rapid cooling suitable for snap-freezing samples.
Rapid cooling is important because it can limit ice-crystal formation before tissues or cells are fully frozen. Limiting these crystals helps preserve sample structure and composition, which matters when the material will later undergo molecular analysis or biochemical assays. The freezing rate therefore influences both temperature reduction and the reliability of downstream biological information.
Unlike cooling by immersion in liquid water, dry ice freezing cools samples through the sublimation of a solid and does not use liquid water as the cooling medium. That distinction is relevant when avoiding immersion during preparation, while the rapid temperature decrease supports preservation of biological structure and composition for later biological work.
An effective workflow pairs rapid cooling with careful handling. After the sample experiences the cooling effect of sublimating dry ice, handling should support its suitability for storage or later analysis. Attention should focus on limiting ice-crystal formation and preventing changes that could compromise biological structure or composition.
Dry ice freezing can be selected for tissues, cells, and other biological samples when preservation is needed for molecular analysis, biochemical assays, or storage. Its role is especially useful when a sample must be cooled quickly without immersion in liquid water. The choice depends on whether preserving structure and composition is important for the planned downstream use.
After freezing, preserved material may support molecular analysis or biochemical assays, and it may also be retained for storage. Interpretation should account for whether ice-crystal formation or other freezing-related changes could have altered the specimen. Careful handling helps maintain the original structure and composition, making subsequent measurements more representative of the biological sample.