31301950と31671288：このプロジェクトは、中国の国家自然科学基金（NSFC）によってサポートされていました。

現在の方法が確立され、私たちの研究室で組織染色のために1,000人以上の筋肉サンプルを収穫し、保存することが確認されています。動物のケアと使用を含むすべての手順は、中国の農業省によって確立されたガイドラインに従いました。 サンプル採取のために1.機器<ol><li>各極低温バイアル上のサンプルのアイデンティティにラベルを付けます。 注：極低温バイアルを特別に凍結切片手順（ 図1A）のために、新鮮な組織サンプルを凍結するように設計されています。バイアルを金型工場（ 図1C）にポリプロピレンで作られています。 </li><li>適切な液体窒素タンク内の液体窒素、安全眼鏡、またはフェイスシールド、冷凍手袋、10cmの鉗子25センチピンセット、発泡スチロールのクーラー（内寸：20センチ×12センチ幅X 13.5センチメートル高い次の装置を得ます;外形寸法：幅×15センチメートル上位24センチ×16センチ）、プラスチックフィルム（幅×厚さ0.1mm長さ2.5cm×0.8 cm）で、メス、及びA4 PVC結合カバー（21センチメートル29.5センチX）（ 図1B）。 </li></ol>筋肉試料の調製<ol><li>先にサンプル収集の液体窒素を5分で発泡スチロールのクーラーを記入してください。 注：液体窒素の一部が離れて沸騰し、新鮮なサンプルがそれに触れるとガスに変わるので、液体窒素の大きな柱が不可欠です。損失を補充する液体窒素の移送の頻度を低減するために、適切なサイズの発泡スチロールのクーラーは、サンプルの数に応じて予め取得されなければなりません。 </li><li>試料が得られたら、優しくA4 PVC結合カバーの上に置きますし、筋線維の方向を観察します。 注：ここでは、豚の最後の腰椎に最初から最長ドリス筋の断面を使用しました。標本は約12センチ、長さは8センチ幅、5センチの高さです。 </li><li>試料Iを介して2つの平行切開を作るためにメスを使用N筋繊維の方向、長さが約3cmと0.6センチメートル離れ。約0.6センチ幅×0.6センチメートル1.5×高cmの長さの長方形に切開筋肉をトリム。 注：筋線維の断面積を測定の信頼性は、主に切開筋肉の繊維配向に依存します。 </li><li>穏やか膜（ 図2A）の長辺に切開筋平行の長手方向軸と、プラスチックフィルムの一片上に試料を置くために10cmの鉗子を使用しています。 注：筋線維の配向性と急速な凍結試料中のクラックを防止する接着機能を固定するのに役立つ保持機能：プラスチックフィルムは2つの機能を有しています。 </li><li>鉗子を使用して、ちょうど入口穴との間、標識された極低温バイアルの下部中央に筋肉組織を配置し、その後しっかりバイアル（ 図2B）をキャップ。 </li></ol> 3.筋肉サンプルを凍結して保存しますS <ol><li> 25センチメートルピンセットを使用して、迅速に液体窒素（約10~20秒）沸騰しなくなるまで待って、予め冷却した発泡スチロールのクーラーに液体窒素中で全体極低温バイアルを水没。 注：凍結バイアルを液体窒素が沸騰しているとき、慎重に10〜20秒間、沸騰液体窒素中でバイアルを浸すフロートします。 </li><li>液体窒素貯蔵タンクや長期保存のために-80℃の冷凍庫に筋肉のサンプルを転送します。 </li></ol> 4.スライドの調製<ol><li> -20℃と-22℃の間にクライオスタットを予冷。 </li><li>取り外し、古いミクロトーム刃を破棄し、クライオスタットでナイフホルダーとアンチロールプレートを拭う、クライオスタットの新しいミクロトーム刃をインストールして、8ミクロンに切断厚さを設定します。 </li><li>液体窒素貯蔵タンクから極低温バイアル中に筋肉のサンプルを転送するか、-80℃の冷凍庫°クライオスタットに、液体窒素中またはドライアイスの上にそれを運びます。 </LI&gt; <li>試料はクライオスタットの温度と平衡に30分待ちます。 注：高い温度は、試料中の氷結晶の形成を引き起こす可能性があるため、標本に触れる可能性のある機器は、事前に冷却しなければなりません。 </li><li>水溶性グリコール及び樹脂（OCT）の最適切断温度製剤下試料ホルダーに試料をマウントします。 8-μmのセクションをカット。 注：CSAFは、筋線維の断面積であるため、筋線維の配向に垂直に切断角度を調整します。 </li><li>室温マイクロスライドの中心に向かってセクションをマウントします。すぐに-80℃の冷凍庫でスライドボックスにスライドを置きます。スライドを室温で乾燥させないでください。 </li></ol>

<ol>
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利害の衝突は、金融またはそれ以外の場合は、著者によって宣言されていません。

ここでは、筋機能の組織学的評価を行うために筋肉組織を凍結保存するための新しい、マルチホールクライオバイアルを記述する。このプロトコルにおいて重要な変性ステップは、マルチホールクリオバイアルに試料を直接液体窒素中に浸漬することです。我々の知る限り、これは既存の凍結方法のうち、筋肉凍結切片のための優れた凍結サンプル（代表的な結果を参照）を取得する最も簡?...

骨格筋は、ビューの栄養と処理ポイントから肉を生産する動物の最も貴重なコンポーネントです。筋肉の成長の効率、そして得られた肉の品質：食肉業界では、二つの特に重要な側面があります。筋肉の主成分としては、筋線維は、成長のパフォーマンスと動物1新鮮な肉質に直接関連しています。例えば、繊維の合計数（TNF）及び繊維の断面積（CSAF）は主に筋肉量と肉の品質を決定します。また、ファイバ型の組成物（FTC）が強く、新鮮な肉質2に影響を与えます。したがって、動物における筋線維特性の操作は、農場1のコア収益性と競争力を高めるために非常に有効な方法です。 現在までに、いくつかの内因性および外因性の要因が筋線維を操作することが確認されているcharacteristICS 1。この操作は、牛3におけるミオスタチン遺伝子 、ヒツジ4 Callipyge遺伝子 、およびブタ5 RYR1及びIGF2遺伝子として、特定の遺伝子を有する動物の標的選択によって達成することができます。また、特定のホルモンとダイエットの制御および治療は、筋線維特性6において重要な役割を果たしています。このように、遺伝的および栄養要因を組み合わせたアプローチは、赤身の肉の量と肉の品質を向上させることができるかもしれません。筋線維の構造の解明は依然として難題であるしかし、筋線維の研究では、食肉産業に限定されています。 筋肉繊維特性は、ミオシンアデノシントリホスファターゼ（ATPアーゼ）アッセイなどの組織化学的方法を用いて同定されます。この方法は、酵素が薄い（6-8ミクロン）の凍結切片に位置しているという事実に依存しています筋線維は、化学的に特定の製品と反応させることができます。しかし、筋肉の水分含有量にかかわらず位置（ すなわち、バック、腹部、または後肢）7の、ブタ、ウサギ、マウス、およびヒトにおいて75％以上です。以前に8,9を説明するように、凍結切片の調製中-成果物を凍結-筋肉のような高水分含有量は一般的に遭遇する問題の原因となります。ほとんどの場合、適切に我々の経験によると、食肉処理場の生産ラインで筋肉組織を凍結することはほとんど不可能です。 ここで紹介するプロトコルは、ハイスループットな方法で凍結切片のための筋肉組織を凍結する私たちの研究室で使用されるシンプルかつ効率的な方法を説明します。この方法のハイライトは、液体窒素中でフラッシュ凍結筋肉組織のために設計された新しいクライオバイアルです。現在のワークフローは、同時に組織を容易にすることができますはっきりと見え、細胞質コンパートメントおよび周囲組織への筋線維の緊密な並置と、優れた筋肉凍結切片のために凍結して処理。液体窒素は、組織と混合しないので、また、このプロトコルは、組織分析のためのオプションの広い配列に適用することができます。

<table><tbody><tr><td>Cryostat Microtome</td><td>&amp;nbsp;Leica</td><td>Leica CM1950</td><td></td></tr><tr><td>Digital Microscope&amp;nbsp;</td><td>Nikon</td><td>Nikon DS-U3</td><td></td></tr><tr><td>&amp;nbsp;Cryogenic Vial&amp;nbsp;&amp;nbsp; Plastic film</td><td></td><td></td><td>Designed by ourself</td></tr><tr><td>Liquid Nitrogen</td><td></td><td></td><td>Commomly-used</td></tr><tr><td>Scalpel</td><td></td><td></td><td>Commomly-used</td></tr><tr><td>10 cm forceps</td><td></td><td></td><td>Commomly-used</td></tr><tr><td>25 cm tweezer</td><td></td><td></td><td>Commomly-used</td></tr><tr><td>Safety glass</td><td></td><td></td><td>Commomly-used</td></tr><tr><td>Freezer gloves</td><td></td><td></td><td>Commomly-used</td></tr></tbody></table>

a multi-hole cryovial eliminates freezing artifacts when muscle tissues are directly immersed in liquid nitrogen

骨格筋生理学の研究は、適切にはっきりと見える細胞質コンパートメントでセクションを取得するために検体を処理する技術的な課題に直面しています。もう一つのハードルは、周囲の組織への筋線維のタイト同格です。組織固定し、パラフィン包埋のプロセスは、筋線維の収縮につながるので、凍結は切片のための筋肉組織を硬化させるのに最適な手段です。しかし、一般的に遭遇する問題、氷の結晶の形成は、理由は筋肉の高含水率の凍結切片の調製の間に発生します。ここで紹介するプロトコルは、最初に適切に液体窒素中でそれらを浸漬することにより、筋肉組織を凍結するための簡単で効率的な方法を説明します。単独で、液体窒素を使用しての問題は、次絶縁体として作用し、組織の冷却を阻害する、組織、窒素ガス障壁の形成を引き起こすことがあります。この「蒸気毛布」効果、NEを回避するために、Wクライオバイアルは、組織表面付近の液体の流れの速度を増大させるように設計しました。これは、バイアルの壁14個の入口穴の総数をパンチングすることによって達成されました。気泡力学によれば、より小さな気泡より少ないチャンスで液体流結果のより高い速度は、ガス障壁を形成します。液体窒素は、入口孔からクリオバイアルに流入すると、組織の周りの流速は、ガス障壁を排除するのに十分に高速です。予め冷却したイソペンタンを用いて、筋肉組織の凍結方法に比べて、このプロトコルは単純で、より効率的であり、スループット様式で筋肉を凍結するために使用することができます。さらに、この方法は、室温で非常に可燃性であるイソペンタン、へのアクセスを持っていない機関に最適です。

クライオバイアル例示および凍結切片の調製の間に筋肉を凍結するための一般的な実験装置は、 図1に示されています。クライオバイアルは、金型工場にポリプロピレンから作られます。各バイアルは、14の入口孔の合計を持っている：一つはキャップ上にあります。別のは一番下にあります。残りの12形成する4本の平行線、互いに90°の4つの穴とそれぞ?...

Watch this Scientific Journal Video about A Multi-hole Cryovial Eliminates Freezing Artifacts when Muscle Tissues are Directly Immersed in Liquid Nitrogen at JoVE.com

A Multi-hole Cryovial Eliminates Freezing Artifacts when Muscle Tissues are Directly Immersed in Liquid Nitrogen

このプロトコルは、液体窒素に直接それらを沈めることにより、筋肉組織を凍結する手順を説明します。このプロトコルはまた、試料の窒素ガス際に液体窒素に接触組織表面の「ブランケット効果」を回避することができ、新たなクライオバイアルを強調しています。

筋肉組織を直接液体窒素中に浸漬されたときにアーティファクトを凍結マルチホールクライオバイアルが不要

Studies on skeletal muscle physiology face the technical challenge of appropriately processing the specimens to obtain sections with clearly visible ...

a-multi-hole-cryovial-eliminates-freezing-artifacts-when-muscle

Universidad de Cartagena UDEC

Research

JoVE Journal

Biology

11.2K ビュー.  Jiangxi Agricultural University. このプロトコルは、液体窒素に直接それらを沈めることにより、筋肉組織を凍結する手順を説明します。このプロトコルはまた、試料の窒素ガス際に液体窒素に接触組織表面の「ブランケット効果」を回避することができ、新たなクライオバイアルを強調しています。 

ビデオ: A Multi-hole Cryovial Eliminates Freezing Artifacts when Muscle Tissues are Directly Immersed in Liquid Nitrogen

Manual Blot-and-Plunge Freezing of Biological Specimens for Single-Particle Cryogenic Electron Microscopy

Imaging biological specimens with electrons for high-resolution structure determination by single-particle cryogenic electron microscopy (cryoEM) requires a thin layer of vitreous ice containing the biomolecules of interest. Despite numerous technological advances in recent years that have propelled single-particle cryoEM to the forefront of structural biology, the methods by which specimens are vitrified for high-resolution imaging often remain the rate-limiting step. Although numerous recent efforts have provided means to overcome hurdles frequently encountered during specimen vitrification, including the development of novel sample supports and innovative vitrification instrumentation, the traditional manually operated plunger remains a staple in the cryoEM community due to the low cost to purchase and ease of operation. Here, we provide detailed methods for using a standard, guillotine-style manually operated blot-and-plunge device for the vitrification of biological specimens for high-resolution imaging by single-particle cryoEM. Additionally, commonly encountered issues and troubleshooting recommendations for when a standard preparation fails to yield a suitable specimen are also described.

This manuscript outlines the blot-and-plunge method to manually freeze biological specimens for single-particle cryogenic electron microscopy.

単粒子低温電子顕微鏡用生体試料の手動ブロットとプランジ凍結

Imaging biological specimens with electrons for high-resolution structure determination by single-particle cryogenic electron microscopy (cryoEM) requires ...

生化学

Electron Cryotomography of Bacterial Cells

While much is already known about the basic metabolism of bacterial cells, many fundamental questions are still surprisingly unanswered, including for instance how they generate and maintain specific cell shapes, establish polarity, segregate their genomes, and divide. In order to understand these phenomena, imaging technologies are needed that bridge the resolution gap between fluorescence light microscopy and higher-resolution methods such as X-ray crystallography and NMR spectroscopy.
Electron cryotomography (ECT) is an emerging technology that does just this, allowing the ultrastructure of cells to be visualized in a near-native state, in three dimensions (3D), with "macromolecular" resolution (~4nm).1, 2 In ECT, cells are imaged in a vitreous, "frozen-hydrated" state in a cryo transmission electron microscope (cryoTEM) at low temperature (&lt; -180&deg;C). For slender cells (up to ~500 nm in thickness3), intact cells are plunge-frozen within media across EM grids in cryogens such as ethane or ethane/propane mixtures. Thicker cells and biofilms can also be imaged in a vitreous state by first "high-pressure freezing" and then, "cryo-sectioning" them. A series of two-dimensional projection images are then collected through the sample as it is incrementally tilted along one or two axes. A three-dimensional reconstruction, or "tomogram" can then be calculated from the images. While ECT requires expensive instrumentation, in recent years, it has been used in a few labs to reveal the structures of various external appendages, the structures of different cell envelopes, the positions and structures of cytoskeletal filaments, and the locations and architectures of large macromolecular assemblies such as flagellar motors, internal compartments and chemoreceptor arrays.1, 2
In this video article we illustrate how to image cells with ECT, including the processes of sample preparation, data collection, tomogram reconstruction, and interpretation of the results through segmentation and in some cases correlation with light microscopy.

We illustrate here how to use electron cryotomography (ECT) to study the ultrastructure of bacterial cells in near-native states, to "macromolecular" (~4 nm) resolution.

細菌細胞の電子Cryotomography

While much is already known about the basic metabolism of bacterial cells, many fundamental questions are still surprisingly unanswered, including for ...

生物学

Tissue Triage and Freezing for Models of Skeletal Muscle Disease

Skeletal muscle is a unique tissue because of its structure and function, which requires specific protocols for tissue collection to obtain optimal results from functional, cellular, molecular, and pathological evaluations. Due to the subtlety of some pathological abnormalities seen in congenital muscle disorders and the potential for fixation to interfere with the recognition of these features, pathological evaluation of frozen muscle is preferable to fixed muscle when evaluating skeletal muscle for congenital muscle disease. Additionally, the potential to produce severe freezing artifacts in muscle requires specific precautions when freezing skeletal muscle for histological examination that are not commonly used when freezing other tissues. This manuscript describes a protocol for rapid freezing of skeletal muscle using isopentane (2-methylbutane) cooled with liquid nitrogen to preserve optimal skeletal muscle morphology. This procedure is also effective for freezing tissue intended for genetic or protein expression studies. Furthermore, we have integrated our freezing protocol into a broader procedure that also describes preferred methods for the short term triage of tissue for (1) single fiber functional studies and (2) myoblast cell culture, with a focus on the minimum effort necessary to collect tissue and transport it to specialized research or reference labs to complete these studies. Overall, this manuscript provides an outline of how fresh tissue can be effectively distributed for a variety of phenotypic studies and thereby provides standard operating procedures (SOPs) for pathological studies related to congenital muscle disease.

The analysis of skeletal muscle tissues to determine structural, functional, and biochemical properties is greatly facilitated by appropriate preparation. This protocol describes appropriate methods to prepare skeletal muscle tissue for a broad range of phenotyping studies.

組織トリアージや骨格筋疾患のモデルのために凍結

Skeletal muscle is a unique tissue because of its structure and function, which requires specific protocols for tissue collection to obtain optimal ...

Tandem High-pressure Freezing and Quick Freeze Substitution of Plant Tissues for Transmission Electron Microscopy

Since the 1940s transmission electron microscopy (TEM) has been providing biologists with ultra-high resolution images of biological materials. Yet, because of laborious and time-consuming protocols that also demand experience in preparation of artifact-free samples, TEM is not considered a user-friendly technique. Traditional sample preparation for TEM used chemical fixatives to preserve cellular structures. High-pressure freezing is the cryofixation of biological samples under high pressures to produce very fast cooling rates, thereby restricting ice formation, which is detrimental to the integrity of cellular ultrastructure. High-pressure freezing and freeze substitution are currently the methods of choice for producing the highest quality morphology in resin sections for TEM. These methods minimize the artifacts normally associated with conventional processing for TEM of thin sections. After cryofixation the frozen water in the sample is replaced with liquid organic solvent at low temperatures, a process called freeze substitution. Freeze substitution is typically carried out over several days in dedicated, costly equipment. A recent innovation allows the process to be completed in three hours, instead of the usual two days. This is typically followed by several more days of sample preparation that includes infiltration and embedding in epoxy resins before sectioning. Here we present a protocol combining high-pressure freezing and quick freeze substitution that enables plant sample fixation to be accomplished within hours. The protocol can readily be adapted for working with other tissues or organisms. Plant tissues are of special concern because of the presence of aerated spaces and water-filled vacuoles that impede ice-free freezing of water. In addition, the process of chemical fixation is especially long in plants due to cell walls impeding the penetration of the chemicals to deep within the tissues. Plant tissues are therefore particularly challenging, but this protocol is reliable and produces samples of the highest quality.

Obtaining high-quality transmission electron microscopy images is challenging, especially in the case of plant cells, which have abundant large water-filled vacuoles and aerated spaces. Tandem high-pressure freezing and quick freeze substitution greatly reduce preparation time of plant samples for TEM while producing samples with excellent ultrastructural preservation.

タンデム高圧凍結および透過型電子顕微鏡のための植物組織の急速凍結置換

Since the 1940s transmission electron microscopy (TEM) has been providing biologists with ultra-high resolution images of biological materials. Yet, ...

Fiber Type and Subcellular-Specific Analysis of Lipid Droplet Content in Skeletal Muscle

Skeletal muscle lipid infiltration, known as myosteatosis, increases with obesity and ageing. Myosteatosis has also recently been discovered as a negative prognostic factor for several other disorders such as cardiovascular disease and cancer. Excessive lipid infiltration decreases muscle mass and strength. It also results in lipotoxicity and insulin resistance depending on total intramyocellular lipid content, lipid droplet (LD) morphology, and subcellular distribution. Fiber type (oxidative vs glycolytic) is also important, since oxidative fibers have a greater capacity to utilize lipids. Because of their crucial implications in pathophysiology, in-depth studies on LD dynamics and function in a fiber type-specific manner are warranted.
Herein, a complete protocol is presented for the quantification of intramyocellular lipid content and analysis of LD morphology and subcellular distribution in a fiber type-specific manner. To this end, serial muscle cryosections were stained with the fluorescent dye Bodipy and antibodies against myosin heavy chain isoforms. This protocol enables the simultaneous processing of different muscles, saving time and avoiding possible artifacts and, thanks to a personalized macro created in Fiji, the automatization of LD analysis is also possible.

Increasing evidence indicates that excessive infiltration of lipids inside skeletal muscle results in lipotoxicity and diabetes. Here, we present a complete protocol, including tissue processing, staining with Bodipy, image acquisition, and analysis, to quantify the size, density, and subcellular distribution of lipid droplets in a fiber-type specific manner.

骨格筋中の脂肪滴含量の線維タイプおよび細胞下特異的分析

Skeletal muscle lipid infiltration, known as myosteatosis, increases with obesity and ageing. Myosteatosis has also recently been discovered as a negative ...

医学

Plunge Freezing: A Tool for the Ultrastructural and Immunolocalization Studies of Suspension Cells in Transmission Electron Microscopy

Transmission Electron Microscopy (TEM) is an extraordinary tool for studying cell ultrastructure, in order to localize proteins and visualize macromolecular complexes at very high resolution. However, to get as close as possible to the native state, perfect sample preservation is required. Conventional electron microscopy (EM) fixation with aldehydes, for instance, does not provide good ultrastructural preservation. The slow penetration of fixatives induces cell reorganization and loss of various cell components. Therefore, conventional EM fixation does not allow for an instantaneous stabilization and preservation of structures and antigenicity. The best choice for examining intracellular events is to use cryofixation followed by the freeze-substitution fixation method that keeps cells in their native state. High-pressure freezing/freeze-substitution, which preserves the integrity of cellular ultrastructure, is the most commonly used method, but requires expensive equipment. Here, an easy-to-use and low-cost freeze fixation method followed by freeze-substitution for suspension cell cultures is presented.

This manuscript describes an easy-to-use and low-cost cryofixation method for visualizing suspension cells by transmission electron microscopy.

プランジ凍結：透過型電子顕微鏡での懸濁細胞の超微細構造と免疫学的研究のためのツール

Transmission Electron Microscopy (TEM) is an extraordinary tool for studying cell ultrastructure, in order to localize proteins and visualize ...

Cryosectioning of Contiguous Regions of a Single Mouse Skeletal Muscle for Gene Expression and Histological Analyses

With this method, consecutive cryosections are collected to enable both microscopy applications for tissue histology and enrichment of RNA for gene expression using adjacent regions from a single mouse skeletal muscle. Typically, it is challenging to achieve adequate homogenization of small skeletal muscle samples because buffer volumes may be too low for efficient grinding applications, yet without sufficient mechanical disruption, the dense tissue architecture of muscle limits penetration of buffer reagents, ultimately causing low RNA yield. By following the protocol reported here, 30 &#956;m sections are collected and pooled allowing cryosectioning and subsequent needle homogenization to mechanically disrupt the muscle, increasing the surface area exposed for buffer penetration. The primary limitations of the technique are that it requires a cryostat, and it is relatively low throughput. However, high-quality RNA can be obtained from small samples of pooled muscle cryosections, making this method accessible for many different skeletal muscles and other tissues. Furthermore, this technique enables matched analyses (e.g., tissue histopathology and gene expression) from adjacent regions of a single skeletal muscle so that measurements can be directly compared across applications to reduce experimental uncertainty and to reduce replicative animal experiments necessary to source a small tissue for multiple applications.

Consecutive cryo-sections are collected to enable histological applications and enrichment of RNA for gene expression measurements using adjacent regions from a single mouse skeletal muscle. High-quality RNA is obtained from 20 - 30 mg of pooled cryosections and measurements are directly compared across applications.

遺伝子発現と組織学的分析のためにシングルマウス骨格筋の連続領域の凍結切片化

With this method, consecutive cryosections are collected to enable both microscopy applications for tissue histology and enrichment of RNA for gene ...

Cryogenic Sample Loading into a Magic Angle Spinning Nuclear Magnetic Resonance Spectrometer that Preserves Cellular Viability

Dynamic nuclear polarization (DNP) can dramatically increase the sensitivity of magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. These sensitivity gains increase as temperatures decrease and are large enough to enable the study of molecules at very low concentrations at the operating temperatures (~100 K) of most commercial DNP-equipped NMR spectrometers. This leads to the possibility of in-cell structural biology on cryopreserved cells for macromolecules at their endogenous levels in their native environments. However, the freezing rates required for cellular cryopreservation are exceeded during typical sample handling for DNP MAS NMR and this results in loss of cellular integrity and viability. This article describes a detailed protocol for the preparation and cryogenic transfer of a frozen sample of mammalian cells into a MAS NMR spectrometer.

Presented here is a protocol for cryogenic transfer of frozen samples into the dynamic nuclear polarization (DNP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) probe. The protocol includes directions for rotor storage prior to the experiment and directions for viability measurements before and after the experiment.

細胞生存率を維持するマジックアングル回転核磁気共鳴分光計への低温サンプルローディング

Dynamic nuclear polarization (DNP) can dramatically increase the sensitivity of magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. ...

Regulating Temperature in the Lab: Preserving Samples Using Cold

Preservation of laboratory samples, specimens, and reagents using extreme cold is routinely performed in biomedical research labs. This video will discuss some of the methods for keeping laboratory samples cold and will explain the correct cooling method to use for each experimental requirement.
For example, cooling agents, such as ice and dry ice, are typically used when keeping samples cold during experiments. This video discusses the physical properties of the most commonly used cooling agents, as well as safety precautions for working with them.
When it comes to keeping samples cold in between experiments, cooling equipment, including laboratory grade refrigerators and freezers can be used to preserve samples for extended period of time. Also discussed in this video are types of samples and reagents that can be stored in the commonly-available laboratory cooling equipment.
Finally, the concept of cryopreservation is introduced as a process through which tissues, cells, and biomolecules are cooled to sub-zero temperatures, thereby effectively stopping all sample-degrading biological activity. Several methods of cryopreservation are discussed that minimize or eliminate the formation of damaging ice crystals.

Preserving Samples Using Cold: Cooling Agents and Instruments, and Cryopreservation

研究室での温度コントロール:サンプルの冷却保存

Preservation of laboratory samples, specimens, and reagents using extreme cold is routinely performed in biomedical research labs.  This video will ...

Education

JoVE Science Education

基礎生物学

一般的な実験技術

Snap Freezing of Muscle Tissue for Sectioning: A Protocol to Obtain Ultrathin Sections of Rapidly Frozen Murine Muscle Tissue

Source: Bonetto, A. et al. <a href="https://jove.unicartagenaproxy.elogim.com/video/54893" target="_blank">The Colon-26 Carcinoma Tumor-bearing Mouse as a Model for the Study of Cancer Cachexia.</a> J. Vis. Exp. (2016)
This video describes the procedure for snap freezing muscle tissue and obtaining its thin sections. The technique can help study cancer-related cachexia in colon cancer mouse models.