A Comparison of Two Gelatin Consolidants for the Preservation of Thermally Altered Skeletal Remains

2020 ◽  
Author(s):  
Natalie Bishop ◽  
Angi Christensen
Keyword(s):  
Skeletal Remains ◽  
Gelatin Solution ◽  
Technical Grade ◽  
Food Grade ◽  
Structural Preservation

A recent study (Topoleski & Christensen 2019) found that applying a food-grade gelatin solution to thermally altered skeletal remains resulted in significantly better structural preservation (reduced fragmentation) during recovery and transport compared to untreated controls. Here we expand upon this research and test whether a technical-grade gelatin would result in even better skeletal evidence preservation. Results show that bones treated with both the food-grade and technical-grade gelatins were better preserved (i.e., had less fragmentation) than untreated controls. Application of the technical-grade gelatin, however, did not result in significantly better preservation than the food-grade gelatin, and is less accessible, more expensive, and more difficult to prepare. Food-grade gelatin is therefore recommended, but other types of gelatins can be equally effective.

Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

1983 ◽  
Vol 41 ◽  
pp. 448-449
Author(s):  
C.W. Akey ◽  
M. Szalay ◽  
S.J. Edelstein
Keyword(s):  
Tannic Acid ◽  
Beef Heart ◽  
X Rays ◽  
Screw Axis ◽  
General Applicability ◽  
Thin Sections ◽  
Beef Liver ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

High-Resolution Scanning Electron Microscopy of Biological Specimens

1988 ◽  
Vol 46 ◽  
pp. 186-187
Author(s):  
M. Müller ◽  
R. Hermann
Keyword(s):  
High Resolution ◽  
Freeze Drying ◽  
Room Temperature ◽  
Structural Information ◽  
Freeze Substitution ◽  
Critical Point Drying ◽  
Sem Study ◽  
Major Factors ◽  
Structural Preservation ◽  
Preparation Techniques

Three major factors must be concomitantly assessed in order to extract relevant structural information from the surface of biological material at high resolution (2-3nm).Procedures based on chemical fixation and dehydration in graded solvent series seem inappropriate when aiming for TEM-like resolution. Cells inevitably shrink up to 30-70% of their initial volume during gehydration; important surface components e.g. glycoproteins may be lost. These problems may be circumvented by preparation techniques based on cryofixation. Freezedrying and freeze-substitution followed by critical point drying yields improved structural preservation in TEM. An appropriate preservation of dimensional integrity may be achieved by freeze-drying at - 85° C. The sample shrinks and may partially collapse as it is warmed to room temperature for subsequent SEM study. Observations at low temperatures are therefore a necessary prerequisite for high fidelity SEM. Compromises however have been unavoidable up until now. Aldehyde prefixation is frequently needed prior to freeze drying, rendering the sample resistant to treatment with distilled water.

A comparison of three cryotechniques (freeze-drying, cryosubstitution, cryosectioning) of specimen preparation for immunolabelling of bacterial antigens of Coxiella burnetii

1994 ◽  
Vol 52 ◽  
pp. 140-141
Author(s):  
T. F. McCaul ◽  
R. J. Gould
Keyword(s):  
Coxiella Burnetii ◽  
Freeze Drying ◽  
Stress Proteins ◽  
Cultured Cells ◽  
High Specificity ◽  
Specimen Preparation ◽  
Bacterial Antigens ◽  
Structural Preservation ◽  
Nuclear Ribonucleoprotein ◽  
Cellular Components

Immuno-electron microscopy has allowed the selective localisation of molecules with high resolution and high specificity. Cryopreparatory methods have provided better retention of antigenicity suitable for precise immunolabelling together with optimal structural preservation of cellular components. Cryosubstitution and cryoultramicrotomy have widely been exploited for immunolabelling. Molecular Distillation Dryer (MDD), a form of freeze-drying technique, has recently been used for immunolabelling of Plasmodium falciparum stress proteins and nuclear ribonucleoprotein particles in cultured cells. In the present study, we report the comparison of all three cryotechniques in the immunolabelling of bacterial antigens of Coxiella burnetii.The highly infectious C. burnetii was prefixed in 3% glutaraldehyde (66 mM cacodylate buffer, pH 6.8 ). The cells were then pre-embedded in 2% low-temperature agarose on Durapore hydrophilic membrane prior to cryofixation using a LifeCell CF100 metal-mirror system. A 1% glutaraldehyde in 100% methanol was used as a medium for cryosubstitution in a Reichert CS Auto Cryosubstitution apparatus.

Freeze-substitution of rye grass and ragweed pollen grains

1990 ◽  
Vol 48 (3) ◽  
pp. 686-687
Author(s):  
Liza B. Martinez ◽  
Susan M. Wick
Keyword(s):  
Cell Function ◽  
Pollen Grains ◽  
Freeze Substitution ◽  
Cell Types ◽  
Rapid Freezing ◽  
Rye Grass ◽  
Acrylic Resins ◽  
Allergenic Proteins ◽  
Cold Embedding ◽  
Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

The limit of the contemporary financial system in Russia

2020 ◽  
Vol 16 (7) ◽  
pp. 1223-1245
Author(s):  
V.V. Smirnov
Keyword(s):  
Cluster Analysis ◽  
Foreign Currency ◽  
Financial System ◽  
Descriptive Statistics ◽  
High Tech ◽  
Monetary Aggregate ◽  
Internal System ◽  
Monetary Relations ◽  
And Cluster Analysis ◽  
Structural Preservation

Subject. The article focuses on the modern financial system of Russia. Objectives. I determine the limit of the contemporary financial system in Russia. Methods. The study is based on methods of descriptive statistics, statistical and cluster analysis. Results. The article shows the possibility of determining the scope of the contemporary financial system in Russia by establishing monetary relations as the order of the internal system and concerted operation of subsystems, preserving the structure of the financial system, maintaining the operational regime, implementing the program and achieving the goal. I found that the Russian financial system correlated with the Angolan one, and the real scope of the contemporary financial system in Russia. Conclusions and Relevance. As an attempt to effectively establish monetary relations and manage them, the limit of the contemporary financial system is related to the possibility of using Monetary Aggregate M0 to maintain the balance of the Central Bank of Russia. To overcome the scope of Russia’s financial system, the economy should have changed its specialization, refocusing it on high-tech export and increasing the foreign currency reserves. This can be done if amendments to Russia’s Constitution are adopted. The findings expand the scope of knowledge and create new competence in the establishment of monetary relations, order of the internal system and concerted interaction of subsystems, structural preservation of the financial system and maintenance of its operational regime.

Aplikasi Pendayagunaan Asam In-Situ pada Kulit Pikel Terbuang untuk Pembuatan Gelatin Pangan

2016 ◽  
Vol 9 (2) ◽  
pp. 187-197
Author(s):  
Sugihartono Sugihartono
Keyword(s):  
Food Industry ◽  
Type A ◽  
Collagen Fibers ◽  
Final Phase ◽  
Acid Base ◽  
Salt Hydrate ◽  
Food Grade ◽  
Hydrolyze Collagen ◽  
Waste Acid

Skinswaste at pre-tanning operations can be processed into food grade gelatin. The degradation of collagen using acid, base, or enzymes produced gelatin. Pickle skins is skins that acidified, the results of the final phase of the pre-tanning operations. The addition of salt on the skin makes the skins pickle not swollen, produced a wide space between collagen fibers and collagen can not be degraded. Thereby directly extract pickle skins or waste will not be obtained gelatin.This study discussed the processing of food gelatin type A pickle skins through the utilization of waste acid it contains. The discussion includes the components of animal skins, pre-tanning waste, acidification of skins, processing gelatin and gelatin from skins picklewaste and usefulness for the food industry. Salt hydrate collagen fibers in the skin pickle including waste can be separated by washing, to a certain extent still acidic skins waste. The remaining acid on the skins pickle waste can be utilized to hydrolyze collagen into gelatin. The resulting gelatin is gelatin type A, that can be used for food industry.ABSTRAKKulit limbah pada operasi pra-penyamakan dapat diolah menjadi gelatin pangan. Pemecahan kolagen menggunakan asam, basa, atau enzim dihasilkan gelatin. Kulit pikel merupakan kulit yang diasamkan, hasil dari tahap akhir operasi pra-penyamakan. Penambahan garam pada kulit pikel menjadikan kulit tidak bengkak, menghasilkan ruang lebar diantara serat kolagen dan menjadikan kolagen tidak dapat terdegradasi. Hal ini berarti ekstrak secara langsung kulit pikel atau limbahnya tidak akan diperoleh gelatin. Dalam kajian ini dibahas pengolahan gelatin pangan tipe A dari kulit pikel limbah melalui pendayagunaan asam yang dikandungnya. Bahasan mencakup komponen kulit hewan, limbah pra-penyamakan, pengasaman kulit, pengolahan gelatin, dan pengolahan gelatin dari kulit pikel limbah melalui pendayagunaan asam yang dikandungnya serta kegunaannya untuk industri pangan. Garam yang menghidrasi serat kolagen pada kulit pikel termasuk limbahnya dapat dipisahkan dengan cara pencucian, sampai batas tertentu kulit limbah masih bersifat asam. Asam yang tersisa pada kulit pikel limbah tersebut dapat didayagunakan untuk menghidrolisis kolagen menjadi gelatin. Gelatin yang dihasilkan adalah gelatin tipe A, dapat digunakan untuk keperluan industri pangan. Kata kunci : Kulit pikel limbah, gelatin, pengasaman, pangan.

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