著者が認めることを何もありません。

1. 買収の監視培養
<ol><li>DMEM + グルタミン (例えばGlutaMAX) の HeLa 細胞を成長 10% (v/v) 熱不活化牛胎児血清および 1% ペニシリンとストレプトマイシン培。</li>
	<li>フィブロネクチン (25 μ g/mL) 1 h で 6 よくガラス底培養皿をコートします。ウェルあたり 2 x 10 の4セルをシードします。</li>
	<li>買収は、中に 3 日おきに媒体を変更します。</li>
	<li>時間経過の取得ビデオの無料のレンズ顕微鏡 (市販) を使用します。 注: これは、レンズ無料計算イメージング法に基づいて Ozcan et al.による記述で16 37 ° C12,15の温度制御でインキュベーターで継続的な監視を実行する変更されました。1.67 μ m の画素ピッチ 6.4 x 4.6 mm2のイメージング領域と相補的金属酸化物半導体 (CMOS) イメージ センサーを提供しています。複数の波長の照明は、マルチチップ光発光ダイオード (Led) デバイス、赤、緑、青の照明を提供するによって提供されます。波長が中心に、452、521, 636 nm それぞれ、25、45、25 のスペクトル帯域幅を持つ nm それぞれ。赤、緑、青 (RGB) Led は、セルから約 5 cm の距離で 150 μ m のピンホールの上にあります。LED に近い測定光は各波長で 10 μ と低く、照明時間は 1 秒当たりの取得。したがって、写真毒性の問題も、細胞培養、レンズ無料ビデオ顕微鏡下で観察すると必要ありません。</li>
	<li>CMOS センサー (図 1) と接触して置く細胞培養容器を入れなさい。レンズ無料取得の品質にとって重要である下部にガラス基板とコンテナーを使用します。プラスチック容器も使用できますが、レンズ無料獲得がこれらのコンテナーの光質の悪さにより低下します。</li>
	<li>ビデオ レンズ無料顕微鏡集録ソフトウェア (市販) が時間経過の取得とホログラフィック再構成を実行するを制御します。ソフトウェア インターフェイスでユーザーが入力する必要があるパラメーターがフレーム レート、実験、細胞培養、すなわち付着性のセルまたは浮遊細胞の種類の期間。</li>
	<li>集録ソフトウェアの入力パラメーターを設定します。1 つ取得 10 分ごとに、「付着」に細胞培養型を設定フレーム レートを設定します。 注: 追跡分析する結果のデータセットのサイズはまだ合理的な信頼性の高いセルに、1 つ取得 10 分ごとのフレーム レートは良い妥協案です。この顕微鏡のレンズ無料セットアップで達成可能な最速のフレーム レートは、1 つの取得は 5 分ごとです。培養細胞の生存率に影響を与えることができる CMOS センサーの過剰加熱の結果、フレーム レートがさらに向上します。</li>
	<li>コマ撮りの集録を開始し、ホログラフィック再構成アルゴリズム (市販) は、細胞培養の位相画像を取得するレンズ無料取得を自動的に処理します。ホログラフィック再構成アルゴリズムの多波長位相検索アルゴリズム17に基づいておりの範囲で RGB 再構成画像を提供します [-π、π +] 29.4 mm2のビューの大きなフィールドを単一セルごとに。レンズ無料で線ホログラフィーの原理は薄いサンプルを照らす (z = 0) (振幅 1 の正規化後) の平面波と短い距離 z 以降の回折強度画像 CMOS センサーで検出する = Z 後、通常 1 mm、サンプルです。セットアップ時に照明が順番に 3 波長に切り替えられた (λ1= 0.450 μ、λ20.540 μ、λ3を = = 0.647 μ m) 同じサンプルの 3 つの回折パターンを測定します。</li>
</ol>2. 細胞培養データ解析
<ol><li>セルの追跡を単一粒子18の自動追跡のためのオープン ソース フィジー プラグイン Trackmate アルゴリズムを使用します。At はまず、フィジー (負荷イメージ シーケンス コマンド) にコマ撮り完全買収を読み込みます。29.7 Mb 通常 400 RGB フレームの機能は、データセットのサイズが大きいため 8 ビットの形式でそれらをロードするより高速です。次に Trackmate フィジー プラグインは、すなわち細胞検出期細胞トラッカー期、細胞検出および計算のトラックに適用されるいくつかのフィルター、細胞追跡アルゴリズムのいくつかの段階でユーザーをガイドします。すべての段階でアルゴリズムを構成し、結果を表示すぐにして、必要に応じて、1 つ簡単に移動できます前後設定を再調整します。Trackmate インタ フェースのさまざまなメニューは HeLa 細胞実験に使用される実際の設定で図 2のとおりです。</li>
	<li>(図 2参照) を次のよう入力ソフトウェアの入力パラメーターを設定します。15 ピクセル、15 ピクセルにギャップを閉じる最大距離と 3.5 にトラックでのスポットの数に 15 ピクセルに推定される blob 直径 0.25 検出しきい値、リンクの最大距離を設定します。 メモ: これらの設定が別の特に '推定 blob 直径」(ここでは 1.67 μ m のピクセルで与えられる) セル サイズに対応する異なる 1 つの実験から明らかに。同じ発言は (ここでは 1.67 μ m のピクセルで与えられる) 2 つの連続するフレーム内のセルで、最大距離を占める旅「リンク最大距離」に適用されます。最適な値は、細胞運動、細胞密度にも依存します。</li>
	<li>細胞追跡プロセスの最後に、3 つのテキスト ファイルの形式で結果を生成 (「解析」ボタンを図 2を参照します).最も有用なファイル、'統計追跡のスポット' は、買収、フレーム数、トラック数 (x, y) それぞれの立場で検出されたすべてのセルの一覧で構成されます。このデータに基づいてセル分割を実行し、(サプルメンタリ コード ファイルを参照してください) 専用のアルゴリズムを使用して細胞分裂を検出します。他の 2 つのファイルがという名前の 'トラックの統計情報にリンク' と 'トラック' の統計情報とトラック、トラック期間など、検出されたギャップ数を扱うすべての結果を含む、最初のフレームなどを追跡。</li>
	<li>セル分割アルゴリズムを使用して、自動的に再構成画像からの細胞の形態を記述するいくつかの指標を抽出する (を参照してください補足コード ファイル)。これらの指標は、細胞表面積 (S)、細胞の長軸の長さ (L)、セルの短軸の長さ (l) とセルの縦横比 (l)。顕微鏡のレンズ無料から回復フェーズは、密度と前述のとおり15試料の層の厚さに比例です。</li>
	<li>細胞の形態学的特徴、に加えて再構成13,19,20から定量細胞乾燥質量 (CDM) 測定を抽出します。 <img alt="Equation 1" src="/files/ftp_upload/56580/56580eq1v3.jpg">イコライザー (1) φ(x,y) が再建された位相シフト19波長 λ と α = 1.8 × 10-4 m3/kg乾燥質量1、屈折率の変化を関連している特定の屈折 19。</li>
	<li>セルの屈折と培地の違いの推定を用いたセル厚を評価します。セル厚h(x,y) と位相シフトの関係は、20で与えられます。 <img alt="Equation 2" src="/files/ftp_upload/56580/56580eq2v3.jpg">式 (2.1) <img alt="Equation 3" src="/files/ftp_upload/56580/56580eq3v3.jpg">式 (2.2) Δn(x,y) = nセル(x、y) - n培地(x、y)、細胞と培地との間の屈折率差。以下では、Δ の定数値を想定n = 0.025、HeLa 細胞核で測定した屈折率からと推定されている (n = 1.35511)、リン酸緩衝生理食塩水 (PBS) 文化メディアの (n = 1.33)。セルの厚さ値は仮定に基づいているように示して、その相対的な変化が意味のある、分裂細胞を検出するために悪用される可能性が。</li>
	<li>専用のアルゴリズムを使用して測定した厚さ 8 μ m より大きいによる細胞の細胞分裂の発生を検出し、細胞分裂を検出するために検出された細胞の分裂に関連付けられているセルのトラックを抽出する (を参照してください補足コード ファイル)まず識別されます、確認してくださいかどうか新しい細胞が密接に空間し、時間。この方法で細胞分裂の検出は、2 つの堅牢な条件に依存します。Lensfree コマ獲得21,22,23に代替と細胞分裂の検出のためのより精巧な方法を適用できます。</li>
</ol>

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著者が明らかに何もありません。

本稿ではそのレンズ無料ビデオ顕微鏡は、細胞の何千もの速度をキャプチャするインキュベーター内使用ことができますを示す.全体的な方法論を記述するために、標準細胞追跡アルゴリズムの 2.7 日コマ撮りによる培養 HeLa 細胞の分析方法を説明しました。結果は、2.2 × 106セル測定と 10,584 細胞周期トラックを備えデータセットです。買収を行った比較的大規模な細胞間距離と Hela ?...

いくつかの細胞周期を通じて培養細胞を監視し、正確に測定セルのサイズとセルの乾燥質量はやりがいのある仕事です。いくつかラベル無料光技術がこのタスク1,2を実行することができる: 位相シフト干渉法3、デジタル ホログラフィー顕微鏡法 (DHM)4,5,6,7quadriwave 横方向せん断干渉8,9定量位相トモグラフィ10,11。これらのメソッドは、哺乳動物細胞の細胞周期の理解に多くの新しい洞察力につながっています。しかし、彼らは、ほとんど追尾法自動セルと結合し、そのスループットは制限を測定するときセル大容量の軌跡1 (N < それぞれ3,4、5の 20,6). 光学手法は大規模な統計と細胞質量軌跡の測定に必要なため (N > 1000)。
本稿では、同時に数千、インキュベーターの中に直接細胞のイメージを作成し、単一のセル数千もの個々 の細胞周期トラックに沿って指標を定量化しレンズ無料ビデオ顕微鏡の機能を示します。顕微鏡のレンズ無料は定量位相イメージング技術の非常に広い視野で密集細胞の位相画像の取得を可能にする (通常数十 mm2、ここの 29.4 mm2)12,13 ,14,15。単一セルのレベルでいくつかのメトリックが決定されます、例えば領域をセル、携帯の乾燥質量、セル厚、セルの長軸の長さとセルの縦横比12,15, それぞれのイメージから。その後、細胞追跡アルゴリズムを適用すると、これらの機能をプロットできますすべての単一セルの実験時間14,15の関数として。さらに、セルのトラックで細胞分裂の発生を検出することにより初期の細胞乾燥質量 (細胞分裂) の直後に、(細胞分裂) の直前に最後のセルの乾燥質量とセルの他の重要な情報を抽出することが可能です。期間、すなわち、2 つの連続した分割15間の時間を周期します。これらのすべての測定値を計算する非常によい統計量 (N > 1000) 以来、ビューの大きなフィールドが通常単一レンズ無料取得 200 に 10,000 細胞の解析を許可。
レンズ無料ビデオ顕微鏡検査に基づいたこの方法を説明するために監視および 2.7 日間の HeLa 細胞培養を定量化するプロトコルについて述べる。データ解析、多波長ホログラフィック再構成、細胞追跡、セル分割と細胞分裂のアルゴリズムに基づいた 4 つのステップ プロセスです。ここで空間分解能とこのレンズ無料ビデオ顕微鏡のセットアップで得られた比較的高速なフレーム レート (10 分ごと 1 つ取得) の標準的な細胞追跡アルゴリズムと互換性があることを示します。このデータセットの完全な分析は完全な細胞周期上 10,584 セル トラックの測定結果します。
要約すれば、レンズ無料ビデオ顕微鏡は何千ものラベル、同期されていないと実験; ごとそのままセルを自動的に監視する強力なツール各セルは、いくつかの細胞周期を追跡されています。我々 の測定はこのように細胞の大規模な人口でセル間変動より重要なことは、しかし、いくつかのセルのパラメーターの平均値を提供します。

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			<td height="20" style="height:20px;width:231px;">Cytonote lens-free video microscope&#160;</td>
			<td style="width:208px;">Iprasense</td>
			<td style="width:156px;"></td>
			<td style="width:80px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Horus acquisition software</td>
			<td>Iprasense</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">6-well glass bottom culture plates</td>
			<td>MatTek corporation</td>
			<td>Part No: P06G-0-14-F&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DMEM + GlutaMAX medium&#160;</td>
			<td>Gibco</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">heat-inactivated fetal calf serum&#160;</td>
			<td>Eurobio</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">penicillin and streptomycin&#160;</td>
			<td>Gibco</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fibronectin&#160;</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Matlab, image processing toolbox&#160;</td>
			<td>Mathworks</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

lens-free video microscopy for the dynamic and quantitative analysis of adherent cell culture

レンズ無料ビデオを紹介ここでは、顕微鏡により直接インキュベーター内の細胞の何千もの速度を同時にキャプチャおよび監視し、いくつかの細胞周期に沿って単一セルを定量化することが可能であります。完全な監視し、2.7 日間の HeLa 細胞培養を定量化に使用プロトコルについて述べる。まず、レンズ無料ビデオ顕微鏡、細胞文化獲得して実行され、次の 4 段階のプロセス データを分析し、: 多波長ホログラフィック再構成、細胞追跡、セル分割と細胞分裂検出アルゴリズム。その結果、以上 10,000 の細胞周期トラックと 2 x 10 以上6細胞形態計測のデータセットの特徴を収集することが可能だと紹介します。

ホログラフィック再構成プロセスのライト フィールドは、スカラー場によって記述されます (、 <img alt="Equation 4" src="/files/ftp_upload/56580/56580eq4v3.jpg"> Aのサンプル、および横の位置から距離z平面上の複雑な値は、 <img alt="Equation 5" src="/files/ftp_upload/56580/56580eq5v3.jpg"> 、波長 λ)。光の伝搬はプロパゲータ カーネルを提供する Huygens フレネル理論によるモ...

Watch this Scientific Journal Video about Lens-free Video Microscopy for the Dynamic and Quantitative Analysis of Adherent Cell Culture at JoVE.com

Lens-free Video Microscopy for the Dynamic and Quantitative Analysis of Adherent Cell Culture

レンズ無料ビデオ顕微鏡は、インキュベーターの中に直接培養細胞を監視することが出来ます。ここで集録し、解析を培養 HeLa 細胞の 2.7 日間の長い取得するために使用完全なプロトコルについて述べる、2.2 x 10 のデータセットにつながる個々 の細胞の形態や 10584 細胞周期の6測定を追跡します。

レンズ無料のビデオ顕微鏡、付着性細胞培養の定量的解析

Here, we demonstrate that lens-free video microscopy enables us to simultaneously capture the kinetics of thousands of cells directly inside the incubator ...

lens-free-video-microscopy-for-dynamic-quantitative-analysis-adherent

Research

JoVE Journal

Biology

9.4K ビュー.  Université Grenoble Alpes. レンズ無料ビデオ顕微鏡は、インキュベーターの中に直接培養細胞を監視することが出来ます。ここで集録し、解析を培養 HeLa 細胞の 2.7 日間の長い取得するために使用完全なプロトコルについて述べる、2.2 x 10 のデータセットにつながる個々 の細胞の形態や 10584 細胞周期の6測定を追跡します。

ビデオ: Lens-free Video Microscopy for the Dynamic and Quantitative Analysis of Adherent Cell Culture

A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing measurement of multiple cellular phenotypes within a single assay. In this study, we utilized HCA to develop a novel assay for neurotoxicity. Neurotoxicity assessment represents an important part of drug safety evaluation, as well as being a significant focus of environmental protection efforts. Additionally, neurotoxicity is also a well-accepted in vitro marker of the development of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Recently, the application of HCA to neuronal screening has been reported. By labeling neuronal cells with &beta;III-tubulin, HCA assays can provide high-throughput, non-subjective, quantitative measurements of parameters such as neuronal number, neurite count and neurite length, all of which can indicate neurotoxic effects. However, the role of astrocytes remains unexplored in these models. Astrocytes have an integral role in the maintenance of central nervous system (CNS) homeostasis, and are associated with both neuroprotection and neurodegradation when they are activated in response to toxic substances or disease states. GFAP is an intermediate filament protein expressed predominantly in the astrocytes of the CNS. Astrocytic activation (gliosis) leads to the upregulation of GFAP, commonly accompanied by astrocyte proliferation and hypertrophy. This process of reactive gliosis has been proposed as an early marker of damage to the nervous system. The traditional method for GFAP quantitation is by immunoassay. This approach is limited by an inability to provide information on cellular localization, morphology and cell number. We determined that HCA could be used to overcome these limitations and to simultaneously measure multiple features associated with gliosis - changes in GFAP expression, astrocyte hypertrophy, and astrocyte proliferation - within a single assay. In co-culture studies, astrocytes have been shown to protect neurons against several types of toxic insult and to critically influence neuronal survival. Recent studies have suggested that the use of astrocytes in an in vitro neurotoxicity test system may prove more relevant to human CNS structure and function than neuronal cells alone. Accordingly, we have developed an HCA assay for co-culture of neurons and astrocytes, comprised of protocols and validated, target-specific detection reagents for profiling &beta;III-tubulin and glial fibrillary acidic protein (GFAP). This assay enables simultaneous analysis of neurotoxicity, neurite outgrowth, gliosis, neuronal and astrocytic morphology and neuronal and astrocytic development in a wide variety of cellular models, representing a novel, non-subjective, high-throughput assay for neurotoxicity assessment. The assay holds great potential for enhanced detection of neurotoxicity and improved productivity in neuroscience research and drug discovery.

This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.

神経毒性の高いコンテンツ分析のための神経とアストロサイト共培養アッセイ

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing ...

生物学

Video Bioinformatics Analysis of Human Embryonic Stem Cell Colony Growth

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer software.  Video bioinformatics is a powerful quantitative approach for extracting spatio-temporal data from video images using computer software to perform dating mining and analysis. In this article, we introduce a video bioinformatics method for quantifying the growth of human embryonic stem cells (hESC) by analyzing time-lapse videos collected in a Nikon BioStation CT incubator equipped with a camera for video imaging. In our experiments, hESC colonies that were attached to Matrigel were filmed for 48 hours in the BioStation CT.  To determine the rate of growth of these colonies, recipes were developed using CL-Quant software which enables users to extract various types of data from video images.  To accurately evaluate colony growth, three recipes were created. The first segmented the image into the colony and background, the second enhanced the image to define colonies throughout the video sequence accurately, and the third measured the number of pixels in the colony over time.  The three recipes were run in sequence on video data collected in a BioStation CT to analyze the rate of growth of individual hESC colonies over 48 hours. To verify the truthfulness of the CL-Quant recipes, the same data were analyzed manually using Adobe Photoshop software. When the data obtained using the CL-Quant recipes and Photoshop were compared, results were virtually identical, indicating the CL-Quant recipes were truthful. The method described here could be applied to any video data to measure growth rates of hESC or other cells that grow in colonies. In addition, other video bioinformatics recipes can be developed in the future for other cell processes such as migration, apoptosis, and cell adhesion.  

Video bioinformatics is the automated processing, analysis, understanding, and data mining of biological spatio-temporal data extracted from microscopic videos. The purpose of this article is to demonstrate a method for measuring human embryonic stem cell colony growth using a video bioinformatics method.

ヒト胚性幹細胞のコロニーの成長のビデオバイオインフォマティクス解析

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer ...

Clonogenic Assay: Adherent Cells

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture1. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811)2. Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant formulation.

The applicability of the clonogenic assay for evaluating reproductive viability has been established for more than 50 years. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cells.

クローン原性アッセイ：付着細胞

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 19561. ...

Quantitative Live Cell Fluorescence-microscopy Analysis of Fission Yeast

Several microscopy techniques are available today that can detect a specific protein within the cell. During the last decade live cell imaging using fluorochromes like Green Fluorescent Protein (GFP) directly attached to the protein of interest has become increasingly popular 1. Using GFP and similar fluorochromes the subcellular localisations and movements of proteins can be detected in a fluorescent microscope. Moreover, also the subnuclear localisation of a certain region of a chromosome can be studied using this technique. GFP is fused to the Lac Repressor protein (LacR) and ectopically expressed in the cell where tandem repeats of the lacO sequence has been inserted into the region of interest on the chromosome2. The LacR-GFP will bind to the lacO repeats and that area of the genome will be visible as a green dot in the fluorescence microscope. Yeast is especially suited for this type of manipulation since homologous recombination is very efficient and thereby enables targeted integration of the lacO repeats and engineered fusion proteins with GFP 3. Here we describe a quantitative method for live cell analysis of fission yeast. Additional protocols for live cell analysis of fission yeast can be found, for example on how to make a movie of the meiotic chromosomal behaviour 4. In this particular experiment we focus on subnuclear organisation and how it is affected during gene induction. We have labelled a gene cluster, named Chr1, by the introduction of lacO binding sites in the vicinity of the genes. The gene cluster is enriched for genes that are induced early during nitrogen starvation of fission yeast 5. In the strain the nuclear membrane (NM) is labelled by the attachment of mCherry to the NM protein Cut11 giving rise to a red fluorescent signal. The Spindle Pole body (SPB) compound Sid4 is fused to Red Fluorescent Protein (Sid4-mRFP) 6. In vegetatively growing yeast cells the centromeres are always attached to the SPB that is embedded in the NM 7. The SPB is identified as a large round structure in the NM. By imaging before and 20 minutes after depletion of the nitrogen source we can determine the distance between the gene cluster (GFP) and the NM/SPB. The mean or median distances before and after nitrogen depletion are compared and we can thus quantify whether or not there is a shift in subcellular localisation of the gene cluster after nitrogen depletion.

The fission yeast, Schizosaccharomyces pombe, is a good model system to study basic cellular processes. Here we describe a method to perform quantitative live cell analysis of fission yeast. In this particular experiment we focus on organisation of the genome within the cell nucleus, but the method can also be used to study cytosolic factors.

分裂酵母の定量的なライブセル蛍光-顕微鏡解析

Several microscopy techniques are available today that can detect a specific protein within the cell. During the last decade live cell imaging using ...

Quantitative Analysis of Random Migration of Cells Using Time-lapse Video Microscopy

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During directional migration, cells move rapidly in response to an extracellular chemotactic signal, or in response to intrinsic cues 3 provided by the basic motility machinery. Random migration occurs when a cell possesses low intrinsic directionality, allowing the cells to explore their local environment.
Cell migration is a complex process, in the initial response cell undergoes polarization and extends protrusions in the direction of migration 2. Traditional methods to measure migration such as the Boyden chamber migration assay is an easy method to measure chemotaxis in vitro, which allows measuring migration as an end point result. However, this approach neither allows measurement of individual migration parameters, nor does it allow to visualization of morphological changes that cell undergoes during migration.
Here, we present a method that allows us to monitor migrating cells in real time using video - time lapse microscopy. Since cell migration and invasion are hallmarks of cancer, this method will be applicable in studying cancer cell migration and invasion in vitro. Random migration of platelets has been considered as one of the parameters of platelet function 4, hence this method could also be helpful in studying platelet functions. This assay has the advantage of being rapid, reliable, reproducible, and does not require optimization of cell numbers. In order to maintain physiologically suitable conditions for cells, the microscope is equipped with CO2 supply and temperature thermostat. Cell movement is monitored by taking pictures using a camera fitted to the microscope at regular intervals. Cell migration can be calculated by measuring average speed and average displacement, which is calculated by Slidebook software.

This method allows monitoring of cells in real time and quantitative measurements of different cell migration parameters such as speed, displacement, and velocity. Unlike the traditional methods, this real time approach is not based on endpoint quantitative migration measurements; instead it allows monitoring and calculating different parameters continuously.

タイムラプスビデオ顕微鏡を用いた細胞のランダムな移行の定量分析

Cell migration is a dynamic process, which is important for embryonic development, tissue repair, immune system function, and tumor invasion 1, 2. During ...

A Quantitative Fitness Analysis Workflow

Quantitative Fitness Analysis (QFA) is an experimental and computational workflow for comparing fitnesses of microbial cultures grown in parallel1,2,3,4. QFA can be applied to focused observations of single cultures but is most useful for genome-wide genetic interaction or drug screens investigating up to thousands of independent cultures. The central experimental method is the inoculation of independent, dilute liquid microbial cultures onto solid agar plates which are incubated and regularly photographed. Photographs from each time-point are analyzed, producing quantitative cell density estimates, which are used to construct growth curves, allowing quantitative fitness measures to be derived. Culture fitnesses can be compared to quantify and rank genetic interaction strengths or drug sensitivities. The effect on culture fitness of any treatments added into substrate agar (e.g. small molecules, antibiotics or nutrients) or applied to plates externally (e.g. UV irradiation, temperature) can be quantified by QFA.
The QFA workflow produces growth rate estimates analogous to those obtained by spectrophotometric measurement of parallel liquid cultures in 96-well or 200-well plate readers. Importantly, QFA has significantly higher throughput compared with such methods. QFA cultures grow on a solid agar surface and are therefore well aerated during growth without the need for stirring or shaking.
QFA throughput is not as high as that of some Synthetic Genetic Array (SGA) screening methods5,6. However, since QFA cultures are heavily diluted before being inoculated onto agar, QFA can capture more complete growth curves, including exponential and saturation phases3. For example, growth curve observations allow culture doubling times to be estimated directly with high precision, as discussed previously1.
Here we present a specific QFA protocol applied to thousands of S. cerevisiae cultures which are automatically handled by robots during inoculation, incubation and imaging. Any of these automated steps can be replaced by an equivalent, manual procedure, with an associated reduction in throughput, and we also present a lower throughput manual protocol. The same QFA software tools can be applied to images captured in either workflow.
We have extensive experience applying QFA to cultures of the budding yeast S. cerevisiae but we expect that QFA will prove equally useful for examining cultures of the fission yeast S. pombe and bacterial cultures.

Quantitative Fitness Analysis (QFA) is a complementary series of experimental and computational methods for estimating microbial culture fitnesses. QFA estimates the effect of genetic mutations, drugs or other applied treatments on microbe growth. Experiments scaling from focussed analysis of single cultures to thousands of parallel cultures can be designed.

定量的なフィットネスの分析ワークフロー

Quantitative Fitness Analysis (QFA) is an experimental and computational workflow for comparing fitnesses of microbial cultures grown in parallel1,2,3,4. ...

Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, traditional chemotherapeutic approaches have been largely unsuccessful. Hormone therapy is effective at early stage, but often fails with the eventual development of hormone-refractory tumors. We have been interested in developing therapeutics targeting specific metabolic deficiency of tumor cells. We recently showed that prostate tumor cells specifically lack an enzyme (argininosuccinate synthase, or ASS) involved in the synthesis of the amino acid arginine1. This condition causes the tumor cells to become dependent on exogenous arginine, and they undergo metabolic stress when free arginine is depleted by arginine deiminase (ADI)1,10. Indeed, we have shown that human prostate cancer cells CWR22Rv1 are effectively killed by ADI with caspase-independent apoptosis and aggressive autophagy (or macroautophagy)1,2,3. Autophagy is an evolutionarily-conserved process that allows cells to metabolize unwanted proteins by lysosomal breakdown during nutritional starvation4,5. Although the essential components of this pathway are well-characterized6,7,8,9, many aspects of the molecular mechanism are still unclear - in particular, what is the role of autophagy in the death-response of prostate cancer cells after ADI treatment? In order to address this question, we required an experimental method to measure the level and extent of autophagic response in cells - and since there are no known molecular markers that can accurately track this process, we chose to develop an imaging-based approach, using quantitative 3D fluorescence microscopy11,12.
Using CWR22Rv1 cells specifically-labeled with fluorescent probes for autophagosomes and lysosomes, we show that 3D image stacks acquired with either widefield deconvolution microscopy (and later, with super-resolution, structured-illumination microscopy) can clearly capture the early stages of autophagy induction. With commercially available digital image analysis applications, we can readily obtain statistical information about autophagosome and lysosome number, size, distribution, and degree of colocalization from any imaged cell. This information allows us to precisely track the progress of autophagy in living cells and enables our continued investigation into the role of autophagy in cancer chemotherapy.

Autophagy is a ubiquitous process that enables cells to degrade and recycle proteins and organelles. We apply advanced fluorescence microscopy to visualize and quantify the small, but essential, physical changes associated with the induction of autophagy, including the formation and distribution of autophagosomes and lysosomes, and their fusion into autolysosomes.

高度な3D蛍光顕微鏡を用いたオートファジーの定量分析

Prostate cancer is the leading form of malignancies among men in the U.S. While surgery carries a significant risk of impotence and incontinence, ...

Intravital Microscopy of the Microcirculation in the Mouse Cremaster Muscle for the Analysis of Peripheral Stem Cell Migration

In the era of intravascular cell application protocols in the context of regenerative cell therapy, the underlying mechanisms of stem cell migration to nonmarrow tissue have not been completely clarified. We describe here the technique of intravital microscopy applied to the mouse cremaster microcirculation for analysis of peripheral bone marrow stem cell migration in vivo. Intravital microscopy of the M. cremaster has been previously introduced in the field of inflammatory research for direct observation of leucocyte interaction with the vascular endothelium. Since sufficient peripheral stem and progenitor cell migration includes similar initial steps of rolling along and firm adhesion at the endothelial lining it is conceivable to apply the M. cremaster model for the observation and quantification of the interaction of intravasculary administered stem cells with the endothelium. As various chemical components can be selectively applied to the target tissue by simple superfusion techniques, it is possible to establish essential microenvironmental preconditions, for initial stem cell recruitment to take place in a living organism outside the bone marrow.

Intravital microscopy of the mouse M. cremaster microcirculation offers a unique and well-standardized in vivo model for the analysis of peripheral bone marrow stem cell migration.

末梢血幹細胞移動の解析のためのマウス精巣挙筋で微小循環の生体顕微鏡

In the era of intravascular cell application protocols in the context of regenerative cell therapy, the underlying mechanisms of stem cell migration to ...

Analysis of the Gap Junction-dependent Transfer of miRNA with 3D-FRAP Microscopy

Small antisense RNAs, like miRNA and siRNA, play an important role in cellular physiology and pathology and, moreover, can be used as therapeutic agents in the treatment of several diseases. The development of new, innovative strategies for miRNA/siRNA therapy is based on an extensive knowledge of the underlying mechanisms. Recent data suggest that small RNAs are exchanged between cells in a gap junction-dependent manner, thereby inducing gene regulatory effects in the recipient cell. Molecular biological techniques and flow cytometric analysis are commonly used to study the intercellular exchange of miRNA. However, these methods do not provide high temporal resolution, which is necessary when studying the gap junctional flux of molecules. Therefore, to investigate the impact of miRNA/siRNA as intercellular signaling molecules, novel tools are needed that will allow for the analysis of these small RNAs at the cellular level. The present protocol describes the application of three-dimensional fluorescence recovery after photobleaching (3D-FRAP) microscopy to elucidating the gap junction-dependent exchange of miRNA molecules between cardiac cells. Importantly, this straightforward and non-invasive live-cell imaging approach allows for the visualization and quantification of the gap junctional shuttling of fluorescently labeled small RNAs in real time, with high spatio-temporal resolution. The data obtained by 3D-FRAP confirm a novel pathway of intercellular gene regulation, where small RNAs act as signaling molecules within the intercellular network.

Here, we describe the application of three-dimensional fluorescence recovery after photobleaching (3D-FRAP) for the analysis of the gap junction-dependent shuttling of miRNA. In contrast to commonly applied methods, 3D-FRAP allows for the quantification of the intercellular transfer of small RNAs in real time, with high spatio-temporal resolution.

3D-FRAP顕微鏡によるmiRNAのギャップジャンクション依存的転写の解析

Small antisense RNAs, like miRNA and siRNA, play an important role in cellular physiology and pathology and, moreover, can be used as therapeutic agents ...

Oligomerization Dynamics of Cell Surface Receptors in Living Cells by Total Internal Reflection Fluorescence Microscopy Combined with Number and Brightness Analysis

Despite the importance and ubiquity of receptor oligomerization, few methods are applicable for detecting clustering events and measuring the degree of clustering. Here, we describe an imaging approach to determine the average oligomeric state of mEGFP-tagged-receptor homocomplexes in the membrane of living cells. The protocol is based on Total Internal Reflection Fluorescence (TIRF) microscopy combined with Number and Brightness (N&#38;B) analysis. N&#38;B is a method similar to fluorescence-correlation spectroscopy (FCS) and photon counting histogram (PCH), which are based on the statistical analysis of the fluctuations of the fluorescence intensity of fluorophores diffusing in and out of an illumination volume during an observation time. In particular, N&#38;B is a simplification of PCH to obtain information on the average number of proteins in oligomeric mixtures. The intensity fluctuation amplitudes are described by the molecular brightness of the fluorophore and the average number of fluorophores within the illumination volume. Thus, N&#38;B considers only the first and second moments of the amplitude distribution, namely, the mean intensity and the variance. This is, at the same time, the strength and the weakness of the method. Because only two moments are considered, N&#38;B cannot determine the molar fraction of unknown oligomers in a mixture, but it only estimates the average oligomerization state of the mixture. Nevertheless, it can be applied to relatively small time series (compared to other moment methods) of images of live cells on a pixel-by-pixel basis, simply by monitoring the time fluctuations of the fluorescence intensity. It reduces the effective time-per-pixel to a few microseconds, allowing acquisition in the time range of seconds to milliseconds, which is necessary for fast oligomerization kinetics. Finally, large cell areas as well as sub-cellular compartments can be explored.

We describe an imaging approach for the determination of the average oligomeric state of mEGFP-tagged-receptor oligomers induced by ligand binding in the plasma membrane of living cells. The protocol is based on Total Internal Reflection Fluorescence (TIRF) microscopy combined with Number and Brightness (N&#38;B) analysis.

数と明るさの分析と組み合わせた全内部反射蛍光顕微鏡による生細胞における細胞表面受容体のオリゴマー化ダイナミクス

Despite the importance and ubiquity of receptor oligomerization, few methods are applicable for detecting clustering events and measuring the degree of ...