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Nature Aug 2021
Topics: Animals; Mammoths; Preservation, Biological; Tooth
PubMed: 34385615
DOI: 10.1038/d41586-021-02206-1 -
Proceedings of the Royal Society of... Jul 1964
Topics: Blood Preservation; Blood Transfusion; Humans; Military Medicine; Nitrogen; Preservation, Biological; Refrigeration
PubMed: 14178960
DOI: No ID Found -
Proceedings of the Royal Society of... Jul 1964
Topics: Blood Preservation; Glycerol; Humans; Military Medicine; Preservation, Biological; Refrigeration
PubMed: 14178961
DOI: No ID Found -
Analytical and Bioanalytical Chemistry Feb 2011Proper collection and preservation techniques are necessary to ensure sample integrity and maintain the stability of analytes until analysis. Data from improperly...
Proper collection and preservation techniques are necessary to ensure sample integrity and maintain the stability of analytes until analysis. Data from improperly collected and preserved samples could lead to faulty conclusions and misinterpretation of the occurrence and fate of the compounds being studied. Because contaminants of emerging concern, such as pharmaceuticals and personal care products (PPCPs) and steroids, generally occur in surface and drinking water at ng/L levels, these compounds in particular require such protocols to accurately assess their concentrations. In this study, sample bottle types, residual oxidant quenching agents, preservation agents, and hold times were assessed for 21 PPCPs and steroids in surface water and finished drinking water. Amber glass bottles were found to have the least effect on target analyte concentrations, while high-density polyethylene bottles had the most impact. Ascorbic acid, sodium thiosulfate, and sodium sulfite were determined to be acceptable quenching agents and preservation with sodium azide at 4 °C led to the stability of the most target compounds. A combination of amber glass bottles, ascorbic acid, and sodium azide preserved analyte concentrations for 28 days in the tested matrices when held at 4 °C. Samples without a preservation agent were determined to be stable for all but two of the analytes when stored in amber glass bottles at 4 °C for 72 h. Results suggest that if improper protocols are utilized, reported concentrations of target PPCPs and steroids may be inaccurate.
Topics: Cosmetics; Pharmaceutical Preparations; Preservation, Biological; Steroids; Water Pollutants, Chemical
PubMed: 21225251
DOI: 10.1007/s00216-010-4608-5 -
Nature Jun 2012
Topics: Artifacts; Biological Specimen Banks; Guidelines as Topic; Humans; Paraffin Embedding; Preservation, Biological; Specimen Handling; Tissue Fixation
PubMed: 22678297
DOI: 10.1038/486141a -
Journal of Medical Entomology May 2024Proper fixing and long-term preservation of entomological evidence are essential in collections and research and crucial in applied fields such as forensic entomology.... (Comparative Study)
Comparative Study
Proper fixing and long-term preservation of entomological evidence are essential in collections and research and crucial in applied fields such as forensic entomology. Incorrectly stored samples may lose important morphological features over time, rendering molecular analyses exceedingly difficult. The most effective method for preserving soft samples such as larvae is fluid preservation. It uses a combination of a wide range of fixatives and storage fluids. However, very little comparative work has been done to determine the effects of long-term storage on sample quality in terms of color, shape, and DNA stability. Moreover, the current golden standard in forensic entomology has been tailored for age estimation of larvae of Diptera, which differ from larvae of Coleoptera in morphology and subsequently in applied methods. We compared the effects of combinations of 6 commonly used fixatives and 6 commonly used storage fluids on midsized larvae of the forensically important beetle, Necrodes littoralis (Linnaeus, 1758), in terms of color, shape, and suitability for DNA analyses over a 2-yr period. We were looking for combinations that can preserve specimens in a satisfactory state, can be used on a regular basis, do not require advanced protection or skills of the personnel, and are not toxic or too harmful to the environment. We found not only several methods that scored significantly better in the tested parameters compared with the golden standard but also several common methods that should be avoided. The effects of agents on each tested category are discussed in detail.
Topics: Animals; Coleoptera; Larva; DNA; Specimen Handling; Forensic Entomology; Preservation, Biological; Time Factors; Color
PubMed: 38085664
DOI: 10.1093/jme/tjad154 -
Cold Spring Harbor Protocols Mar 2017Three-dimensional imaging of cells using electron tomography enables analysis of cell structure at unprecedented resolution. The preparation of cells for tomography...
Three-dimensional imaging of cells using electron tomography enables analysis of cell structure at unprecedented resolution. The preparation of cells for tomography using rapid freezing followed by freeze-substitution is an essential first step to ensure the optimal preservation of the cell structure for 3D studies. This protocol outlines a method for obtaining well-preserved cells using high-pressure freezing followed by freeze-substitution. We have found that this method is particularly well suited for electron tomography studies and has the added bonus of preserving antigenicity for immuno-electron microscopy. The steps involved in imaging cells and performing tomographic analysis of cellular structures are also outlined.
Topics: Electron Microscope Tomography; Freeze Substitution; Freezing; Fungal Structures; Hydrostatic Pressure; Imaging, Three-Dimensional; Preservation, Biological; Saccharomyces cerevisiae
PubMed: 28250212
DOI: 10.1101/pdb.prot085589 -
Journal of Animal Science Apr 1992Two methods to preserve gastrointestinal tract (GIT) organs and tissues, plastic coating (PC) and plastination (PN), were investigated and compared. Specimens to be...
Two methods to preserve gastrointestinal tract (GIT) organs and tissues, plastic coating (PC) and plastination (PN), were investigated and compared. Specimens to be preserved were removed from animals within 2 h of death and immediately cleaned with water. Digesta contents were removed by flushing desired portions of GIT with water until the exiting water was clear. In the PC method, cleaned specimens were dehydrated by immersion in an isopropanol solution, dried with forced air after positioning and orientation as in situ, and finally coated on the outer and inner surfaces with a clear plastic material. In the PN procedure, specimens were filled with, and submerged in, a low-formaldehyde fixative, then dehydrated by immersion in a cold acetone solution. Dehydrated specimens were immersed in silicone and placed in a freeze drier for impregnation under low vacuum, followed by overnight gas curing with a silicone crosslinker. Finally, viewing windows were cut out with a scalpel in GIT preserved by both methods. Preserved GIT and tissues had an appearance similar to their appearance in vivo. The PC method was simple and inexpensive. Plastinated specimens were more flexible, durable, and lifelike than those preserved by the PC method. In addition, many body parts, such as muscles, nerves, bones, ligaments, and central nervous system specimens, were preserved by PN. Both methods were found to be useful tools for postmortem studies of tissues and GIT organs.
Topics: 1-Propanol; Acetone; Animals; Cattle; Desiccation; Digestive System; Freeze Drying; Horses; Plastics; Preservation, Biological; Sheep; Silicones; Swine
PubMed: 1582928
DOI: 10.2527/1992.7041011x -
PeerJ 2022The transport and storage of samples in temperatures of minus 80 °C is commonly considered as the gold standard for microbiome studies. However, studies conducting...
BACKGROUND
The transport and storage of samples in temperatures of minus 80 °C is commonly considered as the gold standard for microbiome studies. However, studies conducting sample collection at remote sites without a reliable cold-chain would benefit from a sample preservation method that allows transport and storage at ambient temperature.
METHODS
In this study we compare alpha diversity and 16S microbiome composition of 20 fecal sample replicates from Damaraland mole-rats () preserved in a minus 80 °C freezer and transported on dry ice to freeze-dried samples that were stored and transported in ambient temperature until DNA extraction.
RESULTS
We found strong correlations between relative abundances of Amplicon Sequence Variants (ASVs) between preservation treatments of the sample, no differences in alpha diversity measures between the two preservation treatments and minor effects of the preservation treatment on beta diversity measures. Our results show that freeze-drying samples can be a useful method for cost-effective transportation and storage of microbiome samples that yields quantitatively almost indistinguishable results in 16S microbiome analyses as those stored in minus 80 °C.
Topics: Feces; Freeze Drying; Preservation, Biological; Microbiota; Refrigeration
PubMed: 35310158
DOI: 10.7717/peerj.13095 -
Folia Histochemica Et Cytobiologica 2014Over the years Transmission Electron Microscopy (TEM) has evolved into a powerful technique for the structural analysis of cells and tissues at various levels of... (Review)
Review
Over the years Transmission Electron Microscopy (TEM) has evolved into a powerful technique for the structural analysis of cells and tissues at various levels of resolution. However, optimal sample preservation is required to achieve results consistent with reality. During the last few decades, conventional preparation methods have provided most of the knowledge about the ultrastructure of organelles, cells and tissues. Nevertheless, some artefacts can be introduced at all stagesofstandard electron microscopy preparation technique. Instead, rapid freezing techniques preserve biological specimens as close as possible to the native state. Our review focuses on different cryo-preparation approaches, starting from vitrification methods dependent on sample size. Afterwards, we discuss Cryo-Electron Microscopy Of VItreous Sections (CEMOVIS) and the main difficulties associated with this technique. Cryo-Focused Ion Beam (cryo-FIB) is described as a potential alternative for CEMOVIS. Another post-processing route for vitrified samples is freeze substitution and embedding in resin for structural analysis or immunolocalization analysis. Cryo-sectioning according to Tokuyasu is a technique dedicated to high efficiency immunogold labelling. Finally, we introduce hybrid techniques, which combine advantages of primary techniques originally dedicated to different approaches. Hybrid approaches permit to perform the study of difficult-to-fix samples and antigens or help optimize the sample preparation protocol for the integrated Laser and Electron Microscopy (iLEM) technique.
Topics: Cryoelectron Microscopy; Cryopreservation; Crystallization; Freezing; Humans; Ice; Microscopy, Electron, Transmission; Preservation, Biological; Tissue Embedding
PubMed: 24802956
DOI: 10.5603/FHC.2014.0001