Chemical and Physical Fixation of Cells and Tissues: An Overview

Huang, Bing; Yeung, Edward C.

doi:10.1007/978-3-319-19944-3_2

Cited by 32 publications

(26 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, samples are often preserved in chemicals such as ethanol or formaldehyde. These preservatives prevent bacterial growth and preserve the structural integrity of tissues, which allows for morphological examination of preserved organisms . If one is interested in reconstructing the ecology of an organism using isotopic analyses from archived specimens, it is therefore imperative to understand if preservatives and long‐term fixatives can alter δ 13 C and δ 15 N values.…”

Section: Introductionmentioning

confidence: 99%

“…Formaldehyde is a non‐coagulant fixing agent that reacts with proteins to form intermolecular cross‐links, which preserve the cellular organization and structure of the tissue. Cross‐linking of proteins and other molecules occurs when a methylene bridge (‐CH 2 ‐) is formed by an aldehyde combining with proteins, usually by binding to nitrogen (Figure ). Since formaldehyde has a low molecular weight (30 g/mol), it can quickly penetrate and bind to tissue, although the formation of methylene bridges occurs more slowly.…”

Section: Introductionmentioning

confidence: 99%

“…Since formaldehyde has a low molecular weight (30 g/mol), it can quickly penetrate and bind to tissue, although the formation of methylene bridges occurs more slowly. Once the methylene bridges are formed, they are thought to remain stable; however, if they are not formed, unfixed proteins can be denatured and coagulated by ethanol or other dehydrating solvents . If carbon is added to the tissue when formaldehyde binds to protein, the direction and magnitude of change in δ 13 C values would depend on the isotopic composition of the formaldehyde, which may vary depending on the chemical stock, relative to the δ 13 C value of the tissue .…”

Section: Introductionmentioning

confidence: 99%

“…Our study focuses on two common chemical preservatives, formaldehyde and ethanol. Formaldehyde is a non-coagulant fixing agent that reacts with proteins to form intermolecular cross-links, 8,23 which preserve the cellular organization and structure of the tissue.…”

Section: Introductionmentioning

confidence: 99%

“…Cross-linking of proteins and other molecules occurs when a methylene bridge (-CH 2 -) is formed by an aldehyde combining with proteins, usually by binding to nitrogen 8,9,23 (Figure 1). Since formaldehyde has a low molecular weight (30 g/mol), it can quickly penetrate and bind to tissue, although the formation of methylene bridges occurs more slowly.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effects of chemical preservation on bulk and amino acid isotope ratios of zooplankton, fish, and squid tissues

Hetherington

Kurle

Ohman

et al. 2019

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

Rationale It is imperative to understand how chemical preservation alters tissue isotopic compositions before using historical samples in ecological studies. Specifically, although compound‐specific isotope analysis of amino acids (CSIA‐AA) is becoming a widely used tool, there is little information on how preservation techniques affect amino acid δ15N values. Methods We evaluated the effects of chemical preservatives on bulk tissue δ13C and δ15N and amino acid δ15N values, measured by gas chromatography/isotope ratio mass spectrometry (GC/IRMS), of (a) tuna (Thunnus albacares) and squid (Dosidicus gigas) muscle tissues that were fixed in formaldehyde and stored in ethanol for 2 years and (b) two copepod species, Calanus pacificus and Eucalanus californicus, which were preserved in formaldehyde for 24–25 years. Results Tissues in formaldehyde‐ethanol had higher bulk δ15N values (+1.4, D. gigas; +1.6‰, T. albacares), higher δ13C values for D. gigas (+0.5‰), and lower δ13C values for T. albacares (−0.8‰) than frozen samples. The bulk δ15N values from copepods were not different those from frozen samples, although the δ13C values from both species were lower (−1.0‰ for E. californicus and −2.2‰ for C. pacificus) than those from frozen samples. The mean amino acid δ15N values from chemically preserved tissues were largely within 1‰ of those of frozen tissues, but the phenylalanine δ15N values were altered to a larger extent (range: 0.5–4.5‰). Conclusions The effects of preservation on bulk δ13C values were variable, where the direction and magnitude of change varied among taxa. The changes in bulk δ15N values associated with chemical preservation were mostly minimal, suggesting that storage in formaldehyde or ethanol will not affect the interpretation of δ15N values used in ecological studies. The preservation effects on amino acid δ15N values were also mostly minimal, mirroring bulk δ15N trends, which is promising for future CSIA‐AA studies of archived specimens. However, there were substantial differences in phenylalanine and valine δ15N values, which we speculate resulted from interference in the chromatographic resolution of unknown compounds rather than alteration of tissue isotopic composition due to chemical preservation.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effects of chemical preservation on bulk and amino acid isotope ratios of zooplankton, fish, and squid tissues

Hetherington

Kurle

Ohman

et al. 2019

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

show abstract

Unfurling an improved method for visualizing mitotic chromosomes in ferns

Ramirez‐Castillo,

Palma‐Rojas,

Seguel

et al. 2024

Appl Plant Sci

View full text Add to dashboard Cite

PremiseCytotaxonomy employs chromosome visualization to study organismal relationships and evolution. Despite the critical value of cytogenetic data, cytotypes are lacking for many plant groups. Here, we present an improved approach for visualizing mitotic chromosomes in ferns, a key lineage of land plants, using the dividing cells of unfurling croziers (fiddleheads).Methods and ResultsOur modified mitotic chromosome preparation incorporates a brief pectinase–cellulase pretreatment, as well as colchicine fixation and the Feulgen reaction to improve the staining and separation of mitotic chromosomes. To demonstrate this easy and efficient assessment, we determined the sporophytic (2n) chromosome number for three fern species: Cheilanthes mollis (2n = 60), Cheilanthes hypoleuca (2n = 120), and Nephrolepis cordifolia (2n = 82).ConclusionsThe new method presented here improves visualizations of mitotic chromosomes from the dividing nuclei of young fern croziers. Fiddleheads are widely accessible in nature and in living collections worldwide, and this modified approach increases their suitability for fern cytotaxonomic studies.

show abstract

Ethanol‐mediated compaction and cross‐linking enhance mechanical properties and degradation resistance while maintaining cytocompatibility of a nucleus pulposus scaffold

2019

View full text Add to dashboard Cite

Intervertebral disc degeneration is a complex, cell‐mediated process originating in the nucleus pulposus (NP) and is associated with extracellular matrix catabolism leading to disc height loss and impaired spine kinematics. Previously, we developed an acellular bovine NP (ABNP) for NP replacement that emulated human NP matrix composition and supported cell seeding; however, its mechanical properties were lower than those reported for human NP. To address this, we investigated ethanol‐mediated compaction and cross‐linking to enhance the ABNP's dynamic mechanical properties and degradation resistance while maintaining its cytocompatibility. First, volumetric and mechanical effects of compaction only were confirmed by evaluating scaffolds after various immersion times in buffered 28% ethanol. It was found that compaction reached equilibrium at ~30% compaction after 45 min, and dynamic mechanical properties significantly increased 2–6× after 120 min of submersion. This was incorporated into a cross‐linking treatment, through which scaffolds were subjected to 120 min precompaction in buffered 28% ethanol prior to carbodiimide cross‐linking. Their dynamic mechanical properties were evaluated before and after accelerated degradation by ADAMTS‐5 or MMP‐13. Cytocompatibility was determined by seeding stem cells onto scaffolds and evaluating viability through metabolic activity and fluorescent staining. Compacted and cross‐linked scaffolds showed significant increases in DMA properties without detrimentally altering their cytocompatibility, and these mechanical gains were maintained following enzymatic exposure. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2488–2499, 2019.

show abstract

Chemical and Physical Fixation of Cells and Tissues: An Overview

Cited by 32 publications

References 81 publications

Effects of chemical preservation on bulk and amino acid isotope ratios of zooplankton, fish, and squid tissues

Effects of chemical preservation on bulk and amino acid isotope ratios of zooplankton, fish, and squid tissues

Unfurling an improved method for visualizing mitotic chromosomes in ferns

Ethanol‐mediated compaction and cross‐linking enhance mechanical properties and degradation resistance while maintaining cytocompatibility of a nucleus pulposus scaffold

Contact Info

Product

Resources

About