우리는 단어 &quot;아나스타시스&quot;세포 사멸의 반전을 설명하는 제안에 대해 목사 랄프 Bohlmann와 목사 제임스 Voelz 감사합니다; 안정적으로 시토크롬 C -GFP을 표현 헬라 세포에 대한 더글라스 R. 녹색; H446 세포 찰스 M. 루딘 에릭 E. 가드너; 비디오에서 만화 그리기에 도움을 헤더 어린 양; 이 원고의 가치있는 토론을위한 유 후이 여진. 이 작품은 선생님 에드워드 Youde 기념 원정대 (HLT), 박사 월터 제토 기념 장학금 (HLT), 풀 브라이트 부여 007-2009 (HLT), 생명 과학 연구 재단의 교제 (HLT)에 의해 지원되었다, NIH는 NS037402 (JMH) 부여 및 NS083373 (JMH), 그리고 홍콩의 대학 보조금위원회 광역 / B-07 / 99 (MCF). 호 램 당나라는 생명 과학 연구 재단의 Shurl와 케이 쿠 르치 재단 연구원이다.

The authors have nothing to disclose.

아나스타시스는 세포 사멸 경로를 활성화 한 세포가 계속해서 죽어가는 과정을 역 생존 현상을 의미한다. 여기서는 생균 촬상 사실 동일인 셀 늦은 단계에서 아폽토시스 세포 사멸의 과정을 역으로 한 후 생존 및 재생을 계속할 수 있음을 확인하기 위해 사용될 수 있다는 것을 증명하고있다. 우리 프로토콜은 아폽토시스를 유도 및 확인을위한 여러 가지 바이오 마커와 세포 사멸의 모니터링 반전...

세포 사멸 ( &quot;죽음에 떨어지는&quot;에 대한 그리스어)는 일반적으로 세포 자살 1-7로 끝나는 단방향 프로세스로 간주됩니다. 이미 세포 사멸 경로의 8,9을 시작했다 세포를 포함, 그렇지 않으면 전체 동물에 죽을 것 여분의 세포의 생존에 프로 죽음 유전자 결과의 유전 중단. 마찬가지로, 유전자 조작 인위적으로 표시 신호를 &quot;날 먹고&quot;또는 자신의 세포 외 기질 접착 성을 잃게 건강한 포유 동물 세포는 모든 세포의 식균 작용 또는 entosis 각각 10, 11에 의해 죽음을 탈출 할 수 있습니다. 그러나, 우리와 다른 사람들은 또한 세포 사멸 12-15의 초기 단계에서 복구 할 수 있습니다 유전자 조작 정상적인 건강한 포유 동물 세포 및 세포 선없이 것을 보여 주었다. 세포는 전형적인 중요 체크 포인트를 통과 한 후 각각의 세포를 추적 할 수있는 도구를 사용하여, 우리는 또한, 세포 사멸 (12, 13)의 후반 단계에서 복구를 증명하고있다해동 2-6 &quot;니나&quot;를 표시합니다. 최종 단계의 세포 사멸이 체크 포인트는 미토콘드리아 시토크롬 C의 릴리스, 카스파의 활성화, 핵 분열 및 세포 사멸 기관의 형성을 포함한다. 우리는 세포 사멸 2-6의 위기에서 세포 사멸이 반전을 설명하기 위해, &quot;생활에 상승&quot;을 의미 그리스어 합성어 &quot;아나스타시스&quot;을 채택했다. 전체 죽어 복구 프로세스가 라이브 세포 이미징에 의해 관찰되지 않는 한,이 세포 사멸 이벤트를 경험하지 못한 세포에서 아나스타시스를받은 세포를 구별하기 위해 도전하고있다. 작품의 수십 년 세포 사멸에 의한 세포 자살의 형태 적 특징은 진화 적으로 보존 된 생화학 및 분자 이벤트 16-19에 의해 구동되는 것을 밝혀졌다. 이러한 이벤트는 손상 또는 d 제거하여 단세포와 다세포 생물의 발달과 homoeostatic 과정을 조절하는 세포의 자기 파괴를 촉진angerous 세포 16-19. 사멸 세포에 쉽게 사멸 1,5,6,16,20의 표준화, 형태 학적, 생화학 및 분자 발현에 의해 구별 될 수 있지만, 현재 아나스타시스 12, 13에 해당 알려진 마커가 없습니다. 중요한 것은, 아나스타시스를받은 세포는 정상적인 건강한 세포, 단지 세포 사멸을 반대로 시작 세포 표시와 같은 세포 사멸 죽어가는 세포 (12, 13)로 나타납니다. 따라서, 새로운 도구는 주어진 생존 세포가 이전의 활성 세포 사멸 과정을 경험했다 확실하게 결론을 내릴 필요가있다. 이 신속하고 대규모 파괴 과정이기 때문에 세포 사멸은 일반적으로 돌이킬 수없는 계단식으로 가정한다. 미토콘드리아는 세포질 (21, 22)에 시토크롬 C와 같은 apoptogenic 요인을 발표 한 후에는 일부 세포가 세포 사멸을 시작하는 것이 일 분 정도 걸릴 수 있지만, 카스파는 5 분 23, 24 내에서 활성화 세포질 다음에 할 수 있고,핵 10 분 25 ~ 27 내에서 응결 및 세포 사멸 잠시 후 25-27. 활성화 된 카스파은 절단과 같은 엔도 뉴 클레아 제 억제제 DFF45 / ICAD 29,30로서 셀룰러 철거 2,28의 주요 목적 구조적 및 기능적 구성 요소를 비활성화하여 아폽토시스를 조율. 카스파는 또한 31, 32 크롬 c의 미토콘드리아 방출을 촉진하는 미토콘드리아에 옭 BCL-2 가족의 BID, 같은 프로 세포 사멸 인자를 활성화합니다. 카스파 활동은 또한 탐식 33 대 식세포 또는 인접 세포에 의한 세포 죽음의 말림을 촉진하기위한 &quot;날 먹고&quot;신호로 포스파티딜 세린의 세포 표면에 노출되는 결과를 초래한다. 또한, 세포 사멸 이벤트는 세포 생체 에너지 대사의 34,35,36를 방해하는 역기능 미토콘드리아는, 렌더링합니다. 따라서, 이러한 파괴를 복구 직관적 아닌 것 같습니다. 원래는 달리 기대관리 포인트, 세포도 늦은 단계에서 사멸 세포 사멸 과정을 취소 할 수 있습니다. 지속적으로 배양 세포를 죽음의 운명을 모니터링함으로써, 우리는 일차 전지 및 세포주 12, 13의 범위에서 후기의 세포 사멸의 가역성을 관찰했다. 죽음의 자극의 제거는, 이러한 미토콘드리아의 분열, 염색질 응축, DNA 손상, 세포막에 blebbing, 포스파티딜 세린의 세포 표면에 노출, 미토콘드리아 시토크롬 C의 릴리스, 카스파 제 활성화, 핵 분열, 세포의 수축으로 세포 사멸의 명백한 기능에서 복구를 허용 세포 사멸 몸과 형성. 이러한 관찰은 아나스타시스의 기능, 결과, 및 메커니즘에 관한 대답없는 질문을 올립니다. 이러한 질문을 해결하기 위해, 전제 조건은 안정적 아나스타시스를받은 세포를 식별하는 것입니다. 여기서는 라이브 현미경 방법 및 이전 말기 아폽토시스 번째 반전 한 세포를 검출하기위한 바이오 센서를 카스파 서술욕실은 살아 남았다.

<table border="0" cellpadding="0" cellspacing="0" width="667">
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			<td height="21" style="height:21px;width:235px;">Name of Material/ Equipment</td>
			<td style="width:139px;">Company</td>
			<td style="width:127px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">LSM780 confocal microscopy</td>
			<td style="width:139px;">Carl Zeiss</td>
			<td style="width:127px;">/</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Glass bottom culture dish</td>
			<td style="width:139px;">MatTek Corporation</td>
			<td style="width:127px;">P35G-0-14-C</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Transparent CultFoi</td>
			<td style="width:139px;">Carl Zeiss</td>
			<td style="width:127px;">000000-1116-084</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">CO2 independent medium</td>
			<td style="width:139px;">Life Technologies</td>
			<td style="width:127px;">18045-088</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">CellTracker</td>
			<td style="width:139px;">Life Technologies</td>
			<td style="width:127px;">C34552</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Mitotracker Red CMXRos</td>
			<td style="width:139px;">Life Technologies</td>
			<td style="width:127px;">M-7512</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Hoechst 33342</td>
			<td style="width:139px;">Life Technologies</td>
			<td style="width:127px;">H1399</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:235px;">Fluorescently labeled annexin V</td>
			<td style="width:139px;">Biovision</td>
			<td style="width:127px;">K201</td>
			<td style="width:167px;"></td>
		</tr>
	</tbody>
</table>

strategies for tracking anastasis, a cell survival phenomenon that reverses apoptosis

아나스타시스 ( &quot;생활에 상승&quot;에 대한 그리스어) 죽어가는 세포의 회복을 의미한다. 이들 세포의 회복 전에, 미토콘드리아 단편화, 세포질 내로 미토콘드리아 사이토 크롬 C의 방출, 카스파 제 활성화, 크로 마틴 응축, DNA 손상, 핵 분열, 세포막에 blebbing, 세포 수축, 세포 표면 노출을 포함한 세포 사멸 중요한 체크 포인트를 통과 한 포스파티딜 세린, 및 세포 사멸 기관의 형성. 세포 사멸 자극함으로써 죽어가는 세포가 사멸하고 잠재적으로 다른 죽음의 메커니즘을 취소 할 수 있도록, 죽음 이전에 제거 될 때 아나스타시스가 발생할 수 있습니다. 따라서, 아나스타시스는 부적절하게 손상된 세포를 유지할 수있는 생리적 치유 과정을 포함 나타납니다. 기능 및 메커니즘 아나스타시스 명백하게 건강한 세포의 복구 후에 과거 사건을 검출하기위한 제한된 도구에 의해 부분적으로 방해, 여전히 불분명하다. 전략 anasta를 검출SIS는 아나스타시스를 변조 생리 메커니즘 연구, 질병 병리 언데드 세포의 유해성과 잠재적 인 치료제를 가능하게 할 것이다. 여기서 우리는 살아있는 세포 현미경 및 포유 동물 세포에 아나스타시스를 식별하고 추적하기위한 포유 동물 카스파 바이오 센서를 사용하여 효과적인 전략을 설명합니다.

세포 사멸의 반전을 연구하기 위해, 조직 배양 세포를 처음으로 세포 사멸을 유발하는 죽음의 자극에 노출되어있다. 세포가 세포 사멸의 특징을 표시 할 때, 신선한 배양액 후 자극을 씻어 후 복구 (그림 1A)를 허용하도록 죽어가는 세포를 배양 적용됩니다. 여기서 다루고있는 핵심 문제는 개별 죽어 배양 된 세포가 세포 사멸을 향해 진행 여전히 아나스타시스을받을 수있는 방법까지?...

Watch this Scientific Journal Video about Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis at JoVE.com

Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis

The term anastasis refers to the phenomenon in which dying cells reverse a cell suicide process at a late stage, repair themselves, and ultimately survive. Here we demonstrate protocols for detecting and tracking cells that undergo anastasis.

추적 아나스타시스, 세포 사멸을 취소 세포 생존 현상에 대한 전략

Anastasis (Greek for &#8220;rising to life&#8221;) refers to the recovery of dying cells. Before these cells recover, they have passed through important ...

strategies-for-tracking-anastasis-cell-survival-phenomenon-that

Research

JoVE Journal

Biology

17.9K 조회수.  Johns Hopkins University Bloomberg School of Public Health. The term anastasis refers to the phenomenon in which dying cells reverse a cell suicide process at a late stage, repair themselves, and ultimately survive. Here we demonstrate protocols for detecting and tracking cells that undergo anastasis. 

비디오: Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis

Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor

Dynamic changes in intracellular calcium concentration in response to various stimuli regulates many cellular processes such as proliferation, differentiation, and apoptosis1. During apoptosis, calcium accumulation in mitochondria promotes the release of pro-apoptotic factors from the mitochondria into the cytosol2. It is therefore of interest to directly measure mitochondrial calcium in living cells in situ during apoptosis. High-resolution fluorescent imaging of cells loaded with dual-excitation ratiometric and non-ratiometric synthetic calcium indicator dyes has been proven to be a reliable and versatile tool to study various aspects of intracellular calcium signaling. Measuring cytosolic calcium fluxes using these techniques is relatively straightforward. However, measuring intramitochondrial calcium levels in intact cells using synthetic calcium indicators such as rhod-2 and rhod-FF is more challenging. Synthetic indicators targeted to mitochondria have blunted responses to repetitive increases in mitochondrial calcium, and disrupt mitochondrial morphology3. Additionally, synthetic indicators tend to leak out of mitochondria over several hours which makes them unsuitable for long-term experiments. Thus, genetically encoded calcium indicators based upon green fluorescent protein (GFP)4 or aequorin5 targeted to mitochondria have greatly facilitated measurement of mitochondrial calcium dynamics. Here, we describe a simple method for real-time measurement of mitochondrial calcium fluxes in response to different stimuli. The method is based on fluorescence microscopy of 'ratiometric-pericam' which is selectively targeted to mitochondria. Ratiometric pericam is a calcium indicator based on a fusion of circularly permuted yellow fluorescent protein and calmodulin4. Binding of calcium to ratiometric pericam causes a shift of its excitation peak from 415 nm to 494 nm, while the emission spectrum, which peaks around 515 nm, remains unchanged. Ratiometric pericam binds a single calcium ion with a dissociation constant in vitro of ~1.7 &mu;M4. These properties of ratiometric pericam allow the quantification of rapid and long-term changes in mitochondrial calcium concentration. Furthermore, we describe adaptation of this methodology to a standard wide-field calcium imaging microscope with commonly available filter sets. Using two distinct agonists, the purinergic agonist ATP and apoptosis-inducing drug staurosporine, we demonstrate that this method is appropriate for monitoring changes in mitochondrial calcium concentration with a temporal resolution of seconds to hours. Furthermore, we also demonstrate that ratiometric pericam is also useful for measuring mitochondrial fission/fragmentation during apoptosis. Thus, ratiometric pericam is particularly well suited for continuous long-term measurement of mitochondrial calcium dynamics during apoptosis.

This protocol describes a method for real-time measurement of mitochondrial calcium fluxes by fluorescent imaging. The method takes advantage of a circularly permutated YFP-based dual-excitation ratiometric calcium sensor (ratiometric pericam-mt) selectively expressed in mitochondria.

유전자 변형으로 인코딩된 칼슘 센서를 사용하여 Apoptosis 동안 Mitochondrial 칼슘 레벨에서 동적 변경 사항 모니터링

Dynamic changes in intracellular calcium concentration in response to various stimuli regulates many cellular processes such as proliferation, ...

연구

생물학

Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death

Studies of cellular apoptosis have been significantly impacted since the introduction of flow cytometry-based methods. Propidium iodide (PI) is widely used in conjunction with Annexin V to determine if cells are viable, apoptotic, or necrotic through differences in plasma membrane integrity and permeability1,2. The Annexin V/ PI protocol is a commonly used approach for studying apoptotic cells3. PI is used more often than other nuclear stains because it is economical, stable and a good indicator of cell viability, based on its capacity to exclude dye in living cells 4,5. The ability of PI to enter a cell is dependent upon the permeability of the membrane; PI does not stain live or early apoptotic cells due to the presence of an intact plasma membrane 1,2,6. In late apoptotic and necrotic cells, the integrity of the plasma and nuclear membranes decreases7,8, allowing PI to pass through the membranes, intercalate into nucleic acids, and display red fluorescence 1,2,9. Unfortunately, we find that conventional Annexin V/ PI protocols lead to a significant number of false positive events (up to 40%), which are associated with PI staining of RNA within the cytoplasmic compartment10. Primary cells and cell lines in a broad range of animal models are affected, with large cells (nuclear: cytoplasmic ratios &lt;0.5) showing the highest occurrence10. Herein, we demonstrate a modified Annexin V/ PI method that provides a significant improvement for assessment of cell death compared to conventional methods. This protocol takes advantage of changes in cellular permeability during cell fixing to promote entry of RNase A into cells following staining. Both the timing and concentration of RNase A have been optimized for removal of cytoplasmic RNA. The result is a significant improvement over conventional Annexin V/ PI protocols (&lt; 5% events with cytoplasmic PI staining).

An accurate method for the assessment of cell death is described. The protocol improves upon conventional Annexin V/ propidium iodide (PI) protocols, which display up to 40% false- positive events in cell lines and primary cells from a broad range of animal models.

세포 죽음의 정확한 평가에 대한 수정 Annexin V / Propidium 이우의 Apoptosis 분석

Studies of cellular apoptosis have been significantly impacted since the introduction of flow cytometry-based methods. Propidium iodide (PI) is widely ...

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1. Apoptosis can be triggered when cells encounter a wide range of cytotoxic stresses. These insults initiate signaling cascades that ultimately cause the release of cytochrome c from the mitochondrial intermembrane space to the cytoplasm2. The release of cytochrome c from mitochondria is a key event that triggers the rapid activation of caspases, the key cellular proteases which ultimately execute cell death3-4.
The pathway of apoptosis is regulated at points upstream and downstream of cytochrome c release from mitochondria5. In order to study the post-mitochondrial regulation of caspase activation, many investigators have turned to direct cytoplasmic microinjection of holocytochrome c (heme-attached) protein into cells6-9. Cytochrome c is normally localized to the mitochondria where attachment of a heme group is necessary to enable it to activate apoptosis10-11. Therefore, to directly activate caspases, it is necessary to inject the holocytochrome c protein instead of its cDNA, because while the expression of cytochrome c from cDNA constructs will result in mitochondrial targeting and heme attachment, it will be sequestered from cytosolic caspases. Thus, the direct cytosolic microinjection of purified heme-attached cytochrome c protein is a useful tool to mimic mitochondrial cytochrome c release and apoptosis without the use of toxic insults which cause cellular and mitochondrial damage.
In this article, we describe a method for the microinjection of cytochrome c protein into cells, using mouse embryonic fibroblasts (MEFs) and primary sympathetic neurons as examples. While this protocol focuses on the injection of cytochrome c for investigations of apoptosis, the techniques shown here can also be easily adapted for microinjection of other proteins of interest.

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

In this protocol, we describe the direct cytoplasmic microinjection of cytochrome c protein into fibroblasts and primary sympathetic neurons. This technique allows for the introduction of cytochrome c protein into the cytoplasm of cells and mimics the release of cytochrome c from mitochondria, which occurs during apoptosis.

시토크롬의 세포질 Microinjection 의한 Apoptosis의 활성화 C</em

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1.  Apoptosis can be triggered when cells encounter a ...

Tracking Morphogenetic Tissue Deformations in the Early Chick Embryo

Embryonic epithelia undergo complex deformations (e.g. bending, twisting, folding, and stretching) to form the primitive organs of the early embryo. Tracking fiducial markers on the surfaces of these cellular sheets is a well-established method for estimating morphogenetic quantities such as growth, contraction, and shear. However, not all surface labeling techniques are readily adaptable to conventional imaging modalities and possess different advantages and limitations. Here, we describe two labeling methods and illustrate the utility of each technique. In the first method, hundreds of fluorescent labels are applied simultaneously to the embryo using magnetic iron particles. These labels are then used to quantity 2-D tissue deformations during morphogenesis. In the second method, polystyrene microspheres are used as contrast agents in non-invasive optical coherence tomography (OCT) imaging to track 3-D tissue deformations. These techniques have been successfully implemented in our lab to studythe physical mechanisms of early head fold, heart, and brain development, and should be adaptable to a wide range morphogenetic processes.

This article describes surface labeling and ex ovo tissue culture in the early chick embryo. Techniques amenable to time-lapse bright field, fluorescence, and optical coherence tomography imaging are presented. Tracking surface labels with high spatiotemporal resolution enables kinematic quantities such as morphogenetic strains (deformations) to be calculated in both two and three dimensions.

초기 여자는 배아에서 Morphogenetic 조직 Deformations 추적

Embryonic epithelia undergo complex deformations (e.g. bending, twisting, folding, and stretching) to form the primitive organs of the early embryo. ...

Formulations for Freeze-drying of Bacteria and Their Influence on Cell Survival

Cellular water can be removed to reversibly inactivate microorganisms to facilitate storage. One such method of removal is freeze-drying, which is considered a gentle dehydration method. To facilitate cell survival during drying, the cells are often formulated beforehand. The formulation forms a matrix that embeds the cells and protects them from various harmful stresses imposed on the cells during freezing and drying. We present here a general method to evaluate the survival rate of cells after freeze-drying and we illustrate it by comparing the results obtained with four different formulations: the disaccharide sucrose, the sucrose derived polymer Ficoll PM400, and the respective polysaccharides hydroxyethyl cellulose (HEC) and hydroxypropyl methyl cellulose (HPMC), on two strains of bacteria, P. putida KT2440 and A. chlorophenolicus A6. In this work we illustrate how to prepare formulations for freeze-drying and how to investigate the mechanisms of cell survival after rehydration by characterizing the formulation using of differential scanning calorimetry (DSC), surface tension measurements, X-ray analysis, and electron microscopy and relating those data to survival rates. The polymers were chosen to get a monomeric structure of the respective polysaccharide resembling sucrose to a varying degrees. Using this method setup we showed that polymers can support cell survival as effectively as disaccharides if certain physical properties of the formulation are controlled1.

Freeze-drying is often an easy and convenient way to obtain dry products of viable bacterial cells. An issue of the process is cell survival. We detail here a procedure to investigate how cell survival during freeze-drying is influenced by the properties of the formulation used.

세포 생존에 박테리아와 그 영향의 동결 건조 공법

Cellular water can be removed to reversibly inactivate microorganisms to facilitate storage. One such method of removal is freeze-drying, which is ...

Optimized Staining and Proliferation Modeling Methods for Cell Division Monitoring using Cell Tracking Dyes

Fluorescent cell tracking dyes, in combination with flow and image cytometry, are powerful tools with which to study the interactions and fates of different cell types in vitro and in vivo.1-5 Although there are literally thousands of publications using such dyes, some of the most commonly encountered cell tracking applications include monitoring of:
<ol>
	<li>stem and progenitor cell quiescence, proliferation and/or differentiation6-8</li>
	<li>antigen-driven membrane transfer9 and/or precursor cell proliferation3,4,10-18 and</li>
	<li>immune regulatory and effector cell function1,18-21.</li>
</ol>
Commercially available cell tracking dyes vary widely in their chemistries and fluorescence properties but the great majority fall into one of two classes based on their mechanism of cell labeling. "Membrane dyes", typified by PKH26, are highly lipophilic dyes that partition stably but non-covalently into cell membranes1,2,11. "Protein dyes", typified by CFSE, are amino-reactive dyes that form stable covalent bonds with cell proteins4,16,18. Each class has its own advantages and limitations. The key to their successful use, particularly in multicolor studies where multiple dyes are used to track different cell types, is therefore to understand the critical issues enabling optimal use of each class2-4,16,18,24.
The protocols included here highlight three common causes of poor or variable results when using cell-tracking dyes. These are:
<ol>
	<li>Failure to achieve bright, uniform, reproducible labeling. This is a necessary starting point for any cell tracking study but requires attention to different variables when using membrane dyes than when using protein dyes or equilibrium binding reagents such as antibodies.</li>
	<li>Suboptimal fluorochrome combinations and/or failure to include critical compensation controls. Tracking dye fluorescence is typically 102 - 103 times brighter than antibody fluorescence. It is therefore essential to verify that the presence of tracking dye does not compromise the ability to detect other probes being used.</li>
	<li>Failure to obtain a good fit with peak modeling software. Such software allows quantitative comparison of proliferative responses across different populations or stimuli based on precursor frequency or other metrics. Obtaining a good fit, however, requires exclusion of dead/dying cells that can distort dye dilution profiles and matching of the assumptions underlying the model with characteristics of the observed dye dilution profile.</li>
</ol>
Examples given here illustrate how these variables can affect results when using membrane and/or protein dyes to monitor cell proliferation.

Successful use of cell tracking dyes to monitor immune cell function and proliferation involves several critical steps. We describe methods for: 1) obtaining bright, uniform, reproducible label-ing with membrane dyes; 2) selecting fluorochromes and data acquisition conditions; and 3) choosing a model to quantify cell proliferation based on dye dilution.

셀 추적 염료를 사용하여 전지 부문 모니터링에 최적화 된 착색 및 확산 모델링 방법

Fluorescent cell tracking dyes, in combination with flow and image cytometry, are powerful tools with which to study the interactions and fates of ...

Cell Tracking Using Photoconvertible Proteins During Zebrafish Development

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of genetically-encoded fluorescent proteins has proven a valuable strategy for elucidating dynamic morphogenetic processes as they occur in the intact organism. During the past decade, the development of photoactivatable and photoconvertible fluorescent proteins has opened the possibility to investigate the fate of discrete subpopulations of tagged proteins1. Unlike photoactivatable proteins, photoconvertible fluorescent proteins (PCFPs) are readily tracked and imaged in their native emission state prior to photoconversion, making it easier to identify and select regions by optical inspection. PCFPs, such as Kaede2, KikGR3, Dendra4 and EosFP5, can be shifted from green to red upon exposure to UV or blue light due to a His-Tyr-Gly tripeptide sequence which forms a green chromophore that can be photoconverted to a red one by a light-catalyzed &beta;-elimination and subsequent extension of a &pi;-conjugated system3. PCFPs and their monomeric variants are useful tools for tracking cells6-10 and studying protein dynamics11-14, respectively. During recent years, PCFPs have been expressed in different animal model, such as zebrafish6, chicken7,8 and mouse9,10 for cell fate tracking. Here we report a protocol for cell-specific photoconversion of PCFPs in the living zebrafish embryo and further tracking of photoconverted proteins at later developmental stages. This methodology allows studying, in a tissue-specific manner, cell biological events underlying morphogenesis in the zebrafish animal model.

Here, we present a method for the photoactivated switch of photoconvertible fluorescent proteins (PCFPs) in the living zebrafish embryo and further tracking of photoconverted protein at specific time points during development. This methodology allows monitoring of cell biological events underlying different developmental processes in a live vertebrate organism.

Zebrafish 개발하는 동안 Photoconvertible 단백질을 사용하여 셀 추적

Embryogenesis is a dynamic process that is best studied by using techniques that allow the documentation of developmental changes in vivo. The use of ...

The Tomato/GFP-FLP/FRT Method for Live Imaging of Mosaic Adult Drosophila Photoreceptor Cells

The Drosophila eye is widely used as a model for studies of development and neuronal degeneration. With the powerful mitotic recombination technique, elegant genetic screens based on clonal analysis have led to the identification of signaling pathways involved in eye development and photoreceptor (PR) differentiation at larval stages. We describe here the Tomato/GFP-FLP/FRT method, which can be used for rapid clonal analysis in the eye of living adult Drosophila. Fluorescent photoreceptor cells are imaged with the cornea neutralization technique, on retinas with mosaic clones generated by flipase-mediated recombination. This method has several major advantages over classical histological sectioning of the retina: it can be used for high-throughput screening and has proved an effective method for identifying the factors regulating PR survival and function. It can be used for kinetic analyses of PR degeneration in the same living animal over several weeks, to demonstrate the requirement for specific genes for PR survival or function in the adult fly. This method is also useful for addressing cell autonomy issues in developmental mutants, such as those in which the establishment of planar cell polarity is affected.

The Tomato/GFP-FLP/FRT Method for Live Imaging of Mosaic Adult Drosophila Photoreceptor Cells

The Tomato/GFP-FLP/FRT method involves visualizing mosaic photoreceptor cells in living Drosophila. It can be used to follow individual photoreceptor cell fates in the retina for days or weeks. This method is ideal for studies of retinal degeneration and neurodegenerative diseases or photoreceptor cell development.

모자이크 성인의 라이브 이미징 토마토 / GFP-FLP / FRT 방법<em&gt; 초파리</em&gt; 광 수용체 (photoreceptor)

The Drosophila eye is widely used as a model  for studies of development and neuronal degeneration. With the powerful mitotic  recombination technique, ...

A Guide to Modern Quantitative Fluorescent Western Blotting with Troubleshooting Strategies

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins within complex biological samples. Since then, western blotting methodology has become a common component of the molecular biologists experimental repertoire. A cursory search of PubMed using the term &#8220;western blot&#8221; suggests that in excess of two hundred and twenty thousand published manuscripts have made use of this technique by the year 2014. Importantly, the last ten years have seen technical imaging advances coupled with the development of sensitive fluorescent labels which have improved sensitivity and yielded even greater ranges of linear detection. The result is a now truly Quantifiable Fluorescence based Western Blot (QFWB) that allows biologists to carry out comparative expression analysis with greater sensitivity and accuracy than ever before. Many &#8220;optimized&#8221; western blotting methodologies exist and are utilized in different laboratories. These often prove difficult to implement due to the requirement of subtle but undocumented procedural amendments. This protocol provides a comprehensive description of an established and robust QFWB method, complete with troubleshooting strategies.

The advancement of western blotting using fluorescence has allowed detection of subtle changes in protein expression enabling quantitative analyses. Here we describe a robust methodology for detection of a range of proteins across a variety of species and tissue types. A strategy to overcome common technical problems is also provided.

문제 해결 전략 현대 양적 형광 웨스턴 블로 팅에 가이드

The late 1970s saw the first publicly reported use of the western blot, a technique for assessing the presence and relative abundance of specific proteins ...

Assessment of Selective mRNA Translation in Mammalian Cells by Polysome Profiling

Regulation of protein synthesis represents a key control point in cellular response to stress. In particular, discreet RNA regulatory elements were shown to allow to selective translation of specific mRNAs, which typically encode for proteins required for a particular stress response. Identification of these mRNAs, as well as the characterization of regulatory mechanisms responsible for selective translation has been at the forefront of molecular biology for some time. Polysome profiling is a cornerstone method in these studies. The goal of polysome profiling is to capture mRNA translation by immobilizing actively translating ribosomes on different transcripts and separate the resulting polyribosomes by ultracentrifugation on a sucrose gradient, thus allowing for a distinction between highly translated transcripts and poorly translated ones. These can then be further characterized by traditional biochemical and molecular biology methods. Importantly, combining polysome profiling with high throughput genomic approaches allows for a large scale analysis of translational regulation.

The ability of cells to adapt to stress is crucial for their survival. Regulation of mRNA translation is one such adaptation strategy, providing for rapid regulation of the proteome. Here, we provide a standardized polysome profiling protocol to identify specific mRNAs that are selectively translated under stress conditions.

Polysom​​e 프로파일 링 포유 동물 세포에 선택적 mRNA의 번역 평가

Regulation of protein synthesis represents a key control point in cellular response to stress. In particular, discreet RNA regulatory elements were shown ...