This work was supported by National Institutes of Health grants GM 100201 to I.F.S, and GM 048071 and GM 065830 to I.P.

우리는 인간의 신경 아세포종 SH-SY5Y 세포에서 지방 칼슘 이벤트를 이미징에 대한 자세한 절차를 제시한다. 이러한 절차는 많은 세포 유형에서 8-10 화상 내 Ca 2 + 신호들에 적용될 수있다. 세포의 1. 준비 <ol><li> 문화 세포들은 공급 업체의 웹 사이트에 나와있는 지침에 따라 이미지를 만들 수 있습니다. </li><li> 촬상 전에 며칠 수확 한 세포는 ㎖의 0.25 % 트립신 / EDTA (2-3 분)를 이용하여 조직 배양 플라스크에서 성장. 박리 후, 트립신을 불 활성화 배양액의 동일 부피를 추가한다. </li><li> 접시 당 3-7 X 104 세포의 밀도로 유리 바닥 촬상 요리에 시드 및 혈구 세포를 이용하여 세포 수를 수행. 이미징 실험 셀을 선택 그들은 60 %의 합류 (2-3 일)에 도달하면. </li></ol> 솔루션 및 시약 2. 준비 <ol><li> 버퍼링 칼슘 함유 HEPES 준비(MM)로 이루어지는 염 용액 (칼슘 -HBSS) : 135의 NaCl, CaCl2를, 하나의 MgCl 2, 10 HEPES, 10 글루코스 5.4의 KCl, 2; pH가 7.4 NaOH로 실온 (RT)에서. 4 ° C에서 포도당과 상점의 추가없이 칼슘 -HBSS를 준비; 사용하기 직전에이 용액에 포도당을 추가합니다. </li><li> 형광 칼슘 지표 칼-520 (1 ㎜)의 막 투과 형태의 가용화, CI-IP (3) (200 μM) 및 EGTA 20 % 플루로 닉 F-127을 함유하는 디메틸 술폭 시드 (100 mM)을 (DMSO). -20 ℃에서, 수분 및 차광 에펜 도르프 튜브 및 저장소로 나누어지는 이러한 시약. </li></ol> 3.로드 세포 막 - 투과, 칼-520 CI-IP 3 EGTA <ol><li> 칼슘 -HBSS에서 각각 5 μM 및 1 μM의 최종 농도로 투과 막 (520) 및 캘-CI-IP (3)의 원액을 희석함으로써 &quot;로딩 완충액&quot;을 준비한다. </li><li> 기음 CUlture 매체와는 칼슘 -HBSS 3 회 미디어를 대체하여 세포를 씻어. </li><li> 칼슘을 제거 -HBSS과 어둠 속에서 실온에서 60 분 동안 로딩 버퍼에 세포를 배양한다. </li><li> 로딩 버퍼를 제거하고 칼슘 -HBSS 3 회 미디어를 대체하여 세포를 씻어. <ol><li> 원하는 경우,이 단계에서, 다음로드 칼슘 -HBSS 5 μM의 최종 농도 원액을 희석함으로써 EGTA / AM과 함께 세포 어두울 RT에서 30-60 분 동안 세포를 배양한다. 이 배양 한 다음, 3.5 단계로 진행하기 전에 세포에게 칼슘 -HBSS로 3 회 씻어. </li></ol></li><li> 로드 시약의 탈 에스테르 화를 허용하는 30 분 동안 칼슘 -HBSS 세포를 부화. </li><li> 촬영 직전, 최종 배양 중에 화장실에 유출했을 수있는 염료를 제거하기 위해 &quot;신선한&quot;칼슘 -HBSS와 칼슘 -HBSS를 교체합니다. </li></ol> 4. 칼슘 </sup&gt; 이미지 획득 <ol><li> 100X APO TIRF의 목적 상 침수 오일의 작은 방울 (NA 1.49)를 놓습니다. </li><li> 거꾸로 현미경의 무대에 영상 접시를 탑재하고 투과광을 사용하여 초점 세포를 가지고. 이것은 촬영 중에 이동을 막도록 접시 촬상을 확보하는 것이 중요하다. </li><li> 고속 EMCCD 카메라를 사용하여 형광 방출 (λ&gt; 내지 510nm)을 캘-520를 자극하고 수집하기 위하여 488 nm의 레이저로 세포를 밝히는. 주 : 현미경을 운영 소프트웨어 패키지는 사용자가 레이저 빔이 어느 ( &quot;WF&quot;음원 정보)보다 중앙 또는 (TIRF 여기 용) 대물 위로 개구의 극단 에지에 도입 될 수 있도록 집속 렌즈를 번역 할 수있다. </li><li> EMCCD 소프트웨어를 사용하여, 칼슘 로컬 이벤트를 캡처하는 데 필요한 시간 해상도로 데이터를 수집하기 위해서 전체 512 X 512 화소로부터 촬상 필드를 감소시킨다. 참고 : 예를 들어, 중앙 쿼드256 X 256 픽셀의 인수는 66 FPS로 수집 속도를 속도가 빨라집니다. 더 나아가 격리 자르기 모드 기능을 사용하여 500 FPS로 EMCCD 카메라의 프레임 레이트를 증가하는 것도 가능하다. </li><li> 자동, 기본 활동의 몇 초를 기록 세포에 자외선 플래시를 제공하고 다른 10 ~ 30 초 동안 계속해서 기록하도록 소프트웨어를 구성 할 수 있습니다. 주 : UV 플래시 현미경의 후면 포트에 다이크로 익 미러를 통해 반사 UV 도입 크세논 아크 광원을 사용하여 전달된다. UV 플래시의 지속 시간과 강도는 지역 칼슘 2 + 이벤트의 원하는 주파수를 연상 경험적으로 조정됩니다. </li><li> 이미지가 오프라인 분석을 위해 스택으로 파일을 저장합니다. </li></ol> 5. 자동 칼슘 이미지 분석 참고 :보고, 프로세스, 많은 상용 소프트웨어 패키지를 사용하여 캡처 된 데이터를 분석 할 수 있습니다. 그러나 빠르게 식별을 자동화하는 알고리즘을 개발했다지역의 칼슘 신호의 D 분석. 이 알고리즘에 사용되는 시공간 필터의 상세한 설명은, ΔF / F 0 및 식별 / 분석 루틴의 발생 11에서 찾을 수있다. 이 알고리즘은 오픈 소스 소프트웨어 플랫폼 파이썬에서 실행하기 위해 개발되었으며 의해 함께 샘플 실험 데이터 및 상세한 사용자 명령과 함께 획득 될 수있는 전자 메일로 해당 저자 (ismith@uci.edu). <ol><li> 파일을 변환하는 다중 평면 .TIFF 파일 형식으로 사용자가 작성한 알고리즘로 가져올 수 있습니다. </li><li> 분석 알고리즘이 들어있는 폴더를 찾아 두 번 다음 Run.exe을 클릭합니다. </li><li> .TIFF 파일을 선택 분석합니다. </li><li> 열기 대화 상자에서 분석 매개 변수를 선택합니다. 샘플 데이터에 대한 기본 매개 변수에 대한 그림 2A를 참조하십시오. </li><li> 흑색 레벨을 결정하는 것은 하나는 N을 수행 시야 부분에 커서를 이동하여 화상 스택 엇갈리게구약 셀을 포함한다 (그림 2B 참조) 또는 수동 &#39;으로 설정 블랙 레벨&#39;프롬프트를 사용하여 블랙 레벨을 입력하여. </li><li> 소프트웨어 (그림 2C-F)에 의한 분석 다음 화면에 네 개의 창을 준수하십시오. C는 세포에서 형광을 휴식의 흑백 이미지 분석되고있다. 이 영상에 흰색 사각형 이벤트에 장착 두 차원 가우시안 함수의 중심 위치로 결정 이벤트 위치입니다. </li><li> 각 이벤트 위치를 클릭하거나 이벤트 사이의주기에 커서 키를 누르십시오. 이렇게하면 배경 감산, 가우스 윈도우 D. 이러한 사이트 업데이트에 각각 형광 비율 변경 (ΔF / F 0) 부드럽게 참고 : 레드 이벤트가 인접 사이트 현지화 활동에서 &#39;블리드를 통해&#39;에서 특정 사이트에서 발생하지 결정된다 강조했다. 선택된 부위에서 형광 신호가 검출 초과 여기서 청색 하부 트레이스 나타낸다검은 선이 특정 사이트에서 발생하는 이벤트를 식별하는 반면, 임계 값 (적색에 해당하는 이벤트를 강조). </li><li> 빨간색을 클릭 이벤트의 시간적 진화를 표시 창 E와 함께 장착 가우스 함수의 공간 프로필과 이벤트의 공간 프로파일이 시간 과정을 통해 평균 표시 창 F를 업데이트 이벤트를 강조했다. </li><li> 수동 유물 분석을 거부 할 수 있도록 확인 된 이벤트를 검토합니다. 오른쪽 빨간색을 클릭하여 이러한 이벤트를 삭제 이벤트를 강조했다. 참고 : 우리의 손에, CA는 하나의 IP (3) R 채널을 통해 2 + 플럭스는 ΔF / F 0 내지 약 0.11로 신호를 불러 일으키는, 그래서 이것보다 상당히 작은 감지 된 &#39;이벤트&#39;는 오탐 (false positive)이 될 가능성이 높다. </li><li> 저장 CellR을 관심의 세포 주위에 그려 &#39;을 선택하여 셀 단위로 당에 데이터 또는 수출&#39;Excel로 저장 &#39;을 선택하여 데이터 내보내기17 ;. 주 : 데이터는 원본 이미지 스택과 같은 폴더에 저장됩니다. </li></ol>

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The authors declare that they have no competing financial interests.

우리는 여기에 설명 형광 칼슘 2 + 지표를 사용하여 배양 된 포유 동물 세포에서 지방의 칼슘 이벤트를 이미징 프로토콜. 또한, 우리는 식별 및 수집 된 데이터의 분석을 자동화하는 직관적 인 사용자 인터페이스와 알고리즘을 설명합니다. 여기에 설명 된 절차는 형광 칼슘 지표 칼-520을 이용하지만, 그러한 FLUO-3, FLUO-4, FLUO-8 및 오레곤 그린 BAPTA-1 등 다른 많은 칼슘...

칼슘 이온 (칼슘)는 도처 유전자 발현, 분비 및 시냅스 가소성 1 오래 지속 변경 사항을 포함 생물학적 과정의 다양한 범위를 조절한다. 칼슘은 다양한 방식으로 행동 할 수있는 방법 중 하나는 칼슘의 다른 공간과 시간 패턴을 통해 세포가 생성 할 수있는 신호를 보낸다. 세포질에서 예를 글로벌 고도 부드러운 근육 조직이 작은 반면에 [칼슘] 트리거 수축, 지역화 된 과도 고도 (현지 칼슘 마이크로 도메인)은 학습과 기억 (3)에 필수적인 유전자 발현을 자극한다. 무료 세포질은 [칼슘 2 +] ~ 100 nm의 휴식에 유지되지만 빠르게 칼슘 통해 세포질로 칼슘의 유입 다음과 같은 몇 가지 마이크로 몰로 세포막에 의해 위치 2+ -permeable 이온 채널을 상승 할 수있다 세포 내에서의 칼슘의 해방tores. 우리 연구소는 소포체 (ER) 막에있는 칼슘 릴리스 채널을 형성하는 이노시톨 1,4,5-trisphosphate 수용체 (IP 3 R)에 초점을 맞추고있다. 수용체의 사이트를 활성화 세포질에 모두 IP (3)과 칼슘의 결합하면, IP (3) R 채널은 칼슘이 ER 루멘 내에서 압수 해방 열립니다. 칼슘 이온의 방출이 공간적으로 (칼슘 2 + 퍼프 4) 칼슘 2의 로컬 세포질 마이크로 도메인을 생성하는 IP 3 루피의 작은 클러스터로 제한 상태로 유지하거나, IP 3 루피의 이웃 클러스터의 근접 정도에 따라 할 수있다 칼슘 유도 된 칼슘 -release (CICR) 5,6의 과정을 통해 여러 퍼프 사이트를 모집하여 세포 전체에 전파. 고급 현미경 imagi과 함께 첸 7 로저에 의해 개발 된 형광 작은 분자 칼슘 지표 염료의 도입,기술을 ng를, 칼슘 신호에 대한 우리의 이해를 촉진 크게있다. 현미경에 사용되는 카메라의 최근 진보는 지금과 같은 전례없는 공간과 시간 해상도 퍼프로 과도 지역 칼슘 이벤트를 이미징 할 수 있습니다. 현재 EMCCD 카메라&gt; 500 프레임 초 -1 (FPS) 및 상보 형 금속 산화 반도체의 새로운 세대에서 128 X 128 픽셀 이미징 할 (CMOS) 카메라가 약간 높게의 비용보다 높은 화소 해상도 및 더 빠른 속도를 제공 할 소음 수준. 총 내부 반사 (TIRF) 현미경과 함께 그것은 이미지에 이제 하나의 칼슘 채널 이벤트 8,9 가능하다. 실무적 수동 처리, 시각적 식별 및 분석 렌더링 자동화 알고리즘 개발에 부담을 배치 대용량 데이터 세트 (분당을 약 1 기가 바이트)를 생성하는 동안이 방법은, 동시에 채널 / 이벤트 수백 이미징을 허용한다. 2 + 지표를 사용하여 그대로 포유류 세포에서 지방의 칼슘 신호를 영상화하기위한 절차 및 프로토콜을 제시한다. 우리는 더 TIRF 기존 넓은 필드 에피 형광 (WF) 현미경 모두 몇 군데 지역 칼슘 이벤트의 식별 및 분석을 자동화 오픈 소스 환경 파이썬으로 개발 한 알고리즘을 보여줍니다. 우리는 IP 칼슘 신호를 -generated 3의 맥락에서 이러한 방법을 설명하지만, 그들은 [칼슘 2 +] 칼슘의 다양한 중 표면에있는 2 + -permeable 이온 채널을 발산 세포질에서 로컬 변경 사항을 연구하기 쉽게 의무가 있습니다 막 또는 세포 내 소기관 8-10.

<table border="0" cellpadding="0" cellspacing="0" width="1055">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:813px;">Name</td>
			<td style="width:124px;">Company</td>
			<td style="width:119px;">Catalogue No.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Human Neuroblastoma SH-SY5Y cells</td>
			<td>ATCC</td>
			<td>CRL-2266</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cal-520/AM</td>
			<td>AAT Bioquest Inc.</td>
			<td>21130</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">ci-IP3 (D-23-O-Isopropylidene-6-O-(2-nitro-4.5-dimethoxy)benzyl-myo-Inositol 145-trisphosphate-Hexakis(propionoxymethyl)</td>
			<td>SiChem</td>
			<td>cag-iso-2-145-10</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMSO/20% pluronic F127</td>
			<td>Invitrogen</td>
			<td>P-3000MP</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EGTA/AM</td>
			<td>Invitrogen</td>
			<td>E-1219</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">35 mm glass-bottom imaging dishes</td>
			<td>MatTek</td>
			<td>P35-1.5-14-C</td>
		</tr>
	</tbody>
</table>

imaging local ca2+ signals in cultured mammalian cells

세포질 칼슘 2 + 이온은 유전자 전사, 전기 흥분과 세포 증식으로 광범위한 프로세스를 제어, 거의 모든 종류의 세포에서 세포 활동의 다양한 측면을 조절한다. 칼슘 신호의 다양성과 특이성은 현지 과도 칼슘 마이크로 도메인 분의 기간에 걸쳐 발생하는 세포 전체의 진동과 파도에 이르기까지 칼슘 신호는 서로 다른 시간과 공간 규모 이상 행동을 생성하는 메커니즘에서 유래 (칼슘 퍼프) 지속 (밀리 초). 전자의 최근 진보는 CCD는 (EMCCD) 카메라는 지금&gt; 500 프레임 초 -1 (FPS)의 속도로 128 X 128 픽셀의 공간 해상도를 가진 지역의 칼슘 신호의 영상을 허용 곱한. 이 접근법은 매우 평행 한 번의 실험에서 채널 또는 퍼프 사이트 수백 동시에 모니터링 할 수있다. 그러나, 데이터의 방대한 양의 생성 (약 1 기가 체육R 최소) 2 + 이벤트 불가능한 로컬 CA의 시각적 식별 및 분석을 렌더링합니다. 여기에 우리가 설명하고 수집, 탐지를위한 절차를 설명하고, 넓은 필드 에피 형광 (WF) 및 총 내부 반사를 모두 사용하여 칼슘 2 + 지표로드 그대로 포유류 세포에서 칼슘에게 2+ 신호를 매개 성 3 로컬 IP 분석 형광 (TIRF) 현미경. 또한, 우리는이 지역의 칼슘 신호의 식별 및 분석을 자동화 오픈 소스 소프트웨어 환경 파이썬에서 개발 한 알고리즘을 설명합니다. 알고리즘은 서브 픽셀 해상도의 칼슘 방출 사이트 편재; 데이터의 사용자 리뷰를 할 수 있습니다; 엑셀과 호환 표의 진폭 및 속도 데이타와 함께 형광 신호의 비율의 시간 시퀀스들을 출력한다.

그림 1A는 CI-IP 3로드 인간의 신경 모세포종 SH-SY5Y 세포에서 칼-520 형광 휴식의 WF 이미지를 보여줍니다. 사진 릴리스로 100 밀리 초 UV 플래시 이러한 세포의 노출은 I-IP 3 (그림 1A에 흰색 원으로 주목) 이산 사이트에서 일시적인 칼슘 2 + 퍼프를 이끌어 냈다. 이 사이트에서 측정 된 형광 추적을 서서히 방출 사이트에서 확산 칼슘 2로 훨씬 느?...

Watch this Scientific Journal Video about Imaging Local Ca2+ Signals in Cultured Mammalian Cells at JoVE.com

Imaging Local Ca2+ Signals in Cultured Mammalian Cells

Here we present techniques for imaging local IP3-mediated Ca2+ events using fluorescence microscopy in intact mammalian cells loaded with Ca2+ indicators together with an algorithm that automates identification and analysis of these events.

이미징 로컬 CA<sup&gt; 2 +</sup&gt; 배양 된 포유 동물 세포에서 신호

Cytosolic Ca2+ ions regulate numerous aspects of cellular activity in almost all cell types, controlling processes as wide-ranging as gene transcription, ...

imaging-local-ca2-signals-in-cultured-mammalian-cells

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JoVE Journal

Biology

Imaging Local Ca2+ Signals in Cultured Mammalian Cells

10.7K 조회수.  University of California, Irvine. Here we present techniques for imaging local IP3-mediated Ca2+ events using fluorescence microscopy in intact mammalian cells loaded with Ca2+ indicators together with an algorithm that automates identification and analysis of these events.

비디오: Imaging Local Ca2+ Signals in Cultured Mammalian Cells

Long-term Imaging Mammalian Cells using Wide-Field Microscopy

Actually what I'm gonna do, mount it in here first and then swap out You. So now I'm gonna aspirate try and be as gentle as possible.Okay. A few seconds just holding.Okay.Alright.So the important features of our lifestyle imaging grid are that, so it's an inverted scope, which means the objective, the samples here in the objective is underneath. So the objective is pointing up and the whole scope, or practically the whole, practically the whole scope, including the objectives and the sample are at 37 degrees. So everything in this plastic box is at 37 degrees.And right on top of the stage we have an air and CO2 mix. That is 5%CO2. So the idea is that the sample is actually in a cell, it's like a cell incubator.And so we have, this is our mixer for the air and the CO2 and, and it gets humidified and heated and then piped onto the, the sample on the stage.Okay. And today we're just gonna be doing fluorescence one channel GFP fluorescence. This is the hose that the CO2 and 5%CO2 goes in and it just fits into the stage holder.That's important. And then we can close these, take these down, and then we go to our first position. And what I'm gonna do is go to the first field, which is my control sample, and I'll pick positions based on what I see on the screen.So I just make sure I actually look into the microscope in each new, well, because the focal plane for each of the wells is different, the, the dish is not perfectly flat on the bottom. So you will need to make fine adjustments when you move from well to the well. So right now I'm on the first, well, what I'll do is I'll focus, so I just hit, I just told, I just turned on the light, the transmitted light for the microscope.And I have make sure all the light is going to the eye pieces. And so I just look in, make sure I get a nice clean field. And then what I'll do is turn that light off, turn the fluorescence light on, make sure the cells that I'm looking at look healthy and they're not apoptotic.And, and I turn that off. And what I do next is send, so now I'm gonna start picking positions, which means I have to te send the light path to the camera. This is the camera right here.So I tell the microscope to send all the camera, they don't see anything in the eye pieces. What I'll do is in the software controlling the microscope, I'll choose the right filter set, which for our purposes is psy. And then set an exposure time.And I know these cells very well and I know that they take a 0.2 second exposure time. So I tell, that's what I tell the software to do. And what I'll do is hit focus.This is, and it's basically just alive. The, A light will turn on and you can, oh, I don't know if you can see cells, but the reason this is a good field is because there's, all the cells are, even in terms of their fluorescence, There are no apoptotic cells. Apoptotic cells tend to be very bright and there's no dirt or schmutz in the field.And you can see that they're actually, this is a metaphase cell and that's a metaphase cell, that's a cell that's probably just exited mitosis. And I can just tell that because it looks like those are, those two sets of chromatin are very nicely oriented to each other. Like they just exited an face.So that's a good field. So, and now that I know that the exposure time and the filter set is correct, and this is gonna be software specific, I'll go and I'll take positions and now the software has memorized the X, Y, Z position of that field. And then when I do pick another field, it's, and I'll, so when I'm picking, when I'm picking new fields, but in the same, well, I'll use the, I'll move the i'll, I'll turn the shutter, I'll open the shutter and I'll look to see what I see on the screen and I'll pick fields based on that versus looking in the field.So I don't see any of my tonics in there. But again, even nicely centered, these cells will go through my PS I continue, here's a good example. Here's a good example of what I would avoid that, see how bright that is?That's very bright. That's probably remnants of an apoptotic cell. And the reason I would avoid that is because since it's so bright, when the software auto focuses, it will autofocus just on that and it won't be in the same plane as all these other cells.And so I won't get any information from that field. That looks nice. There's a, this is a pro metaphase right here, That's A metaphase.So, and I'm gonna take three positions per well. So that was three positions and now I'm going to go to my next Well, so you can, so what I will probably do is take images every 10 minutes. So it's a compromise.Lifestyle imaging is always a compromise, right? You have to image, you have to keep the cells healthy, especially if you're interested in mitosis. So you have to minimize their exposure to the fluorescent line.And, but you wanna get information. So you have to take images, you have to, so you have to compromise, you have to make a choice about what you want to capture, what kind of information you wanna capture. For our purposes, mitosis tends to take about an hour.So if we're taking 10 minute intervals, that's pretty good. We see prophase, we see metaphase, we see anaphase, and we can, we can see when there are, there are treatments or drugs or siRNAs that affect those specific cell cycle stages. So for our purposes, that's enough, but we always want more.We always want more positions or finer time and interval or something like that. So it's a compromise. So, and then I'll hit start.And so our software, it does an autofocusing pass on the first pass. So once I hit start, it should start auto autofocusing and you'll see the shutter open, open and close between auto focusing. So I'll hit start.So that's the shutter opening and closing. The Z motor is engaging and it's actually trying to find the plane with the most contrast, which will be the most in focus. You can actually see on the screen going in and out of finding the best plane of focus that might be worrisome.So what it does is it, it drives the Z motor to find the best, the most in focus plane focus, well the most in image. And then it acquires picture there and then it learns that Z position. And then we'll use that Z position for the next 12 passes.And then we'll do the auto focusing pass again. What Kind of experiments do they do? Okay, so our lab is mostly interested in understanding what regulates mitic progression, or at least I'm most interested in understanding that.So with live cell imaging and especially our multi position, long-term imaging scope, you can take, you can film cells for two or three days entering anding mitosis, and you can image multiple rounds of mitosis so you can understand. And then you can put drugs or RNAs or any kind of perturbations on the cells that you would like to study. So you can understand how, how those drugs or, or genes are, are important in regulating mitotic progression.Because it's not fixed cell work and live cell work, you can understand what, when you need to have a perturbation to affect mitosis or what stage of mitosis is affected. So it's really powerful in that respect. What, what are the main technical elements of this experiments?What are the possible problems? Well, the biggest problem besides getting the rig set up, getting the rig set up is not trivial. A lot of people have the rig, but just making sure it works well for your application.The financial element is not, you know, is not small. So there's the setting up of the apparatus and then, and then once you gather the data, there's a real data analysis issue. It takes these movie, if, so, if you're gathering 40 movies each with 30 cells, so you have 40 in 40 fields that you just filmed and each of those fields has 30 cells, then you have to sit down with each one of those movies and look at each one of those cells in that movie.So it takes a really long time to do data analysis. And that's, so it takes a week to analyze data that it took you two days to collect. So there's a, that's a very big obstacle in terms of gathering lots of data.So it's not, while it's high throughput data collection, it's not high throughput analysis. So what would you make to make this experiment really high throughput? So our lab is in the process of developing a program that does the data analysis automatically.And it's a pretty decent program. It's not perfect. The human eye is always better, but it's getting there.So What are the interesting application of this experiment? Maybe other fields you can mention? Besides cell division?You mean for the, oh, for the live cell imaging? Yes.Well, you can do cell motility assays. You can, depending on the, the microscopy that's involved, you can, you know, look at how cells, you could look at tumor development if you really wanted to.But there, you, you're, if as long as you have the right imaging set up, you can, you're pretty much not limited in terms of anything. Our scope happens to be just a wide field and we use 20 by 20 x objective. So it's a pretty low resolution set up, but that's sufficient for what we need to see.So there are, but there definitely aren't, you wouldn't be limited. Anything that has any dynamic kind of experiment, which is biology, it would be, would really benefit from lifestyle imaging. So calcium imaging, although you couldn't do it on our apparatus, that's a live cell.You definitely need live cell imaging for that. Like I said, patient assays, motility assays, those kinds of things would really benefit from live cell imaging. Would you like to tell a few words about your previous experience?How long do you work on these techniques? What do you you work on before? Wow.So in my PhD I didn't work.I did a lot of confocal microscopy, but no lifestyle imaging. And so during my postdoc I was, I helped Dr.King get this apparatus that, that we just used to set up these fragment, get that up and running. And, and so during my postdoc, I had a lot of experience with both widefield with TimeLapse imaging on our scope, which is the widefield and also TimeLapse imaging with confocal microscopy.And I would say that it's really powerful. You get a lot of information, but it's not easy to get working perfectly. So it really requires a lot of attention and a lot of attention to details at every little step of the process.And, and then you still have problems. So it's a tough application, but you can really get, if, if it's what you need to have to, to study your problem, your scientific problem, then it, it's invaluable in that respect, but it's tough. So find someone who knows what they're doing and use them.That's my advice. So good.

와이드 필드 현미경을 사용하여 장기 이미징 포유 동물 세포

연구

생물학

Live Imaging of Dense-core Vesicles in Primary Cultured Hippocampal Neurons

Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images.  Vital fluorescent probes, particularly green fluorescent protein (GFP) have revolutionized cell biology stemming from the ability to label specific intracellular compartments and cellular structures. For example, the live imaging of GFP (and its spectral variants) chimeras have allowed for a dynamic 
analysis of the cytoskeleton, organelle transport, and membrane dynamics in a multitude of organisms and cell types [1-3].  Although live imaging has become prevalent, this approach still poses many technical challenges, particularly in primary cultured neurons.  One challenge is the expression of GFP-tagged proteins in post-mitotic neurons; the other is the ability to capture fluorescent images while minimizing phototoxicity, photobleaching, 
and maintaining general cell health.  Here we provide a protocol that describes a lipid-based transfection method that yields a relatively low transfection rate (~0.5%), however is ideal for the imaging of fully polarized neurons.  A low transfection rate is essential so that single axons and dendrites can be characterized as to their orientation to the cell body to confirm directionality of transport, i.e., anterograde v. retrograde.  Our approach to imaging 
GFP expressing neurons relies on a standard wide-field fluorescent microscope outfitted with a CCD camera, image capture software, and a heated imaging chamber. We have imaged a wide variety of organelles or structures, for example, dense-core vesicles, mitochondria, growth cones, and actin without any special optics or excitation requirements other than a fluorescent light source. Additionally, spectrally-distinct, fluorescently 
labeled proteins, e.g., GFP and dsRed-tagged proteins, can be visualized near simultaneously to characterize co-transport or other coordinated cellular events.  The imaging approach described here is flexible for a variety of imaging applications and can be adopted by a laboratory for relatively little cost provided a microscope is available.

Live cell imaging is of particular utility when studying the dynamics of organelle trafficking. Here we describe a protocol for live imaging of dense-core vesicles in cultured neurons using wide-field fluorescence microscopy. This protocol is flexible and can be adapted to image other organelles such as mitochondria, endosomes, and peroxisomes.

기본 교양 Hippocampal 신경에 덴스 코어 Vesicles의 라이브 영상

Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images.  ...

Techniques for Imaging Ca2+ Signaling in Human Sperm

Fluorescence microscopy of cells loaded with fluorescent, Ca2+-sensitive dyes is used for measurement of spatial and temporal aspects of Ca2+ signaling in live cells. Here we describe the method used in our laboratories for loading suspensions of human sperm with Ca2+-reporting dyes and measuring the fluorescence signal during physiological stimulation. Motile cells are isolated by direct swim-up and incubated under capacitating conditions for 0-24 h, depending upon the experiment. The cell-permeant AM (acetoxy methyl ester) ester form of the Ca2+-reporting dye is then added to a cell aliquot and a period of 1 h is allowed for loading of the dye into the cytoplasm. We use visible wavelength dyes to minimize photo-damage to the cells, but this means that ratiometric recording is not possible. Advantages and disadvantages of this approach are discussed. During the loading period cells are introduced into an imaging chamber and allowed to adhere to a poly-D-lysine coated coverslip. At the end of the loading period excess dye and loose cells are removed by connection of the chamber to the perfusion apparatus. The chamber is perfused continuously, stimuli and modified salines are then added to the perfusion header. Experiments are recorded by time-lapse acquisition of fluorescence images and analyzed in detail offline, by manually drawing regions of interest. Data are normalized to pre-stimulus levels such that, for each cell (or part of a cell), a graph showing the Ca2+ response as % change in fluorescence is obtained.

Techniques for Imaging Ca2+ Signaling in Human Sperm

Stimulus-evoked [Ca2+]i signals of individual human sperm are assessed. Motile cells are loaded with Ca2+-sensitive fluorescent dye (AM-ester method) and immobilised in a perfusable chamber. Cells are imaged by time-lapse fluorescence microscopy and stimulated via the perfusing medium. Responses of single cells (or regions) are analysed offline using Excel.

이미징 CA의 기술 2 + 인간 정자의 시그널링

Fluorescence microscopy of cells loaded with fluorescent, Ca2+-sensitive dyes is used for measurement of spatial and temporal aspects of Ca2+ signaling in ...

MISSION esiRNA for RNAi Screening in Mammalian Cells

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as small interfering RNAs (siRNAs). The short double-stranded RNAs originate from longer double stranded precursors by the activity of Dicer, a protein of the RNase III family of endonucleases. The resulting fragments are components of the RNA-induced silencing complex (RISC), directing it to the cognate target mRNA. RISC cleaves the target mRNA thereby reducing the expression of the encoded protein1,2,3. RNAi has become a powerful and widely used experimental method for loss of gene function studies in mammalian cells utilizing small interfering RNAs.
Currently two main methods are available for the production of small interfering RNAs. One method involves chemical synthesis, whereas an alternative method employs endonucleolytic cleavage of target specific long double-stranded RNAs by RNase III in vitro. Thereby, a diverse pool of siRNA-like oligonucleotides is produced which is also known as endoribonuclease-prepared siRNA or esiRNA. A comparison of efficacy of chemically derived siRNAs and esiRNAs shows that both triggers are potent in target-gene silencing. Differences can, however, be seen when comparing specificity. Many single chemically synthesized siRNAs produce prominent off-target effects, whereas the complex mixture inherent in esiRNAs leads to a more specific knockdown10.
In this study, we present the design of genome-scale MISSION esiRNA libraries and its utilization for RNAi screening exemplified by a DNA-content screen for the identification of genes involved in cell cycle progression. We show how to optimize the transfection protocol and the assay for screening in high throughput. We also demonstrate how large data-sets can be evaluated statistically and present methods to validate primary hits. Finally, we give potential starting points for further functional characterizations of validated hits.

Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results.

포유 동물 세포에서 RNAi 심사를위한 선교 esiRNA

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as ...

Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to replenish depleted endoplasmic reticulum (ER) or sarcoplasmic reticulum (SR) Ca2+ stores1,2. Since Ca2+ is a ubiquitous second messenger, it is not surprising to see that SOCE plays important roles in a variety of cellular processes, including proliferation, apoptosis, gene transcription and motility. Due to its wide occurrence in nearly all cell types, including epithelial cells and skeletal muscles, this pathway has received great interest3,4. However, the heterogeneity of SOCE characteristics in different cell types and the physiological function are still not clear5-7.
The functional channel properties of SOCE can be revealed by patch-clamp studies, whereas a large body of knowledge about this pathway has been gained by fluorescence-based intracellular Ca2+ measurements because of its convenience and feasibility for high-throughput screening. The objective of this report is to summarize a few fluorescence-based methods to measure the activation of SOCE in monolayer cells, suspended cells and muscle fibers5,8-10. The most commonly used of these fluorescence methods is to directly monitor the dynamics of intracellular Ca2+ using the ratio of F340nm and F380nm (510 nm for emission wavelength) of the ratiometric Ca2+ indicator Fura-2. To isolate the activity of unidirectional SOCE from intracellular Ca2+ release and Ca2+ extrusion, a Mn2+ quenching assay is frequently used. Mn2+ is known to be able to permeate into cells via SOCE while it is impervious to the surface membrane extrusion processes or to ER uptake by Ca2+ pumps due to its very high affinity with Fura-2. As a result, the quenching of Fura-2 fluorescence induced by the entry of extracellular Mn2+ into the cells represents a measurement of activity of SOCE9. Ratiometric measurement and the Mn+2 quenching assays can be performed on a cuvette-based spectrofluorometer in a cell population mode or in a microscope-based system to visualize single cells. The advantage of single cell measurements is that individual cells subjected to gene manipulations can be selected using GFP or RFP reporters, allowing studies in genetically modified or mutated cells. The spatiotemporal characteristics of SOCE in structurally specialized skeletal muscle can be achieved in skinned muscle fibers by simultaneously monitoring the fluorescence of two low affinity Ca2+ indicators targeted to specific compartments of the muscle fiber, such as Fluo-5N in the SR and Rhod-5N in the transverse tubules9,11,12.

The extent of store-operated Ca2+ entry (SOCE) can be monitored using fluorescent Ca2+ indicators. Mn2+ quenching of such indicators assays SOCE in cultured cells and skeletal muscle fibers. A technique allowing spatial and temporal resolution of SOCE by confocal imaging of mechanically skinned muscle fibers is also described.

라이브 세포의 저장소로 작동하는 칼슘 항목의 형광 기반의 측정 : 교양 암 세포에서 골격근 섬유에

Store operated Ca2+ entry (SOCE), earlier termed capacitative Ca2+ entry, is a tightly regulated mechanism for influx of extracellular Ca2+ into cells to ...

Analysis of Cell Cycle Position in Mammalian Cells

The regulation of cell proliferation is central to tissue morphogenesis during the development of multicellular organisms. Furthermore, loss of control of cell proliferation underlies the pathology of diseases like cancer. As such there is great need to be able to investigate cell proliferation and quantitate the proportion of cells in each phase of the cell cycle. It is also of vital importance to indistinguishably identify cells that are replicating their DNA within a larger population. Since a cell&prime;s decision to proliferate is made in the G1 phase immediately before initiating DNA synthesis and progressing through the rest of the cell cycle, detection of DNA synthesis at this stage allows for an unambiguous determination of the status of growth regulation in cell culture experiments.
DNA content in cells can be readily quantitated by flow cytometry of cells stained with propidium iodide, a fluorescent DNA intercalating dye. Similarly, active DNA synthesis can be quantitated by culturing cells in the presence of radioactive thymidine, harvesting the cells, and measuring the incorporation of radioactivity into an acid insoluble fraction. We have considerable expertise with cell cycle analysis and recommend a different approach. We Investigate cell proliferation using bromodeoxyuridine/fluorodeoxyuridine (abbreviated simply as BrdU) staining that detects the incorporation of these thymine analogs into recently synthesized DNA. Labeling and staining cells with BrdU, combined with total DNA staining by propidium iodide and analysis by flow cytometry1 offers the most accurate measure of cells in the various stages of the cell cycle. It is our preferred method because it combines the detection of active DNA synthesis, through antibody based staining of BrdU, with total DNA content from propidium iodide. This allows for the clear separation of cells in G1 from early S phase, or late S phase from G2/M. Furthermore, this approach can be utilized to investigate the effects of many different cell stimuli and pharmacologic agents on the regulation of progression through these different cell cycle phases.
In this report we describe methods for labeling and staining cultured cells, as well as their analysis by flow cytometry. We also include experimental examples of how this method can be used to measure the effects of growth inhibiting signals from cytokines such as TGF-&beta;1, and proliferative inhibitors such as the cyclin dependent kinase inhibitor, p27KIP1. We also include an alternate protocol that allows for the analysis of cell cycle position in a sub-population of cells within a larger culture5. In this case, we demonstrate how to detect a cell cycle arrest in cells transfected with the retinoblastoma gene even when greatly outnumbered by untransfected cells in the same culture. These examples illustrate the many ways that DNA staining and flow cytometry can be utilized and adapted to investigate fundamental questions of mammalian cell cycle control.

Determining the cell cycle position of a population of cells, or understanding how signals affect proliferation, can be readily measured by flow cytometry using this protocol. We report a simple experimental approach to staining cells and quantifying their position in the cell cycle.

포유 동물 세포의 세포주기의 위치 분석

The regulation of cell proliferation is central to tissue morphogenesis during the development of multicellular organisms. Furthermore, loss of control of ...

Automated Analysis of Dynamic Ca2+ Signals in Image Sequences

Intracellular Ca2+ signals are commonly studied with fluorescent Ca2+ indicator dyes and microscopy techniques. However, quantitative analysis of Ca2+ imaging data is time consuming and subject to bias. Automated signal analysis algorithms based on region of interest (ROI) detection have been implemented for one-dimensional line scan measurements, but there is no current algorithm which integrates optimized identification and analysis of ROIs in two-dimensional image sequences. Here an algorithm for rapid acquisition and analysis of ROIs in image sequences is described. It utilizes ellipses fit to noise filtered signals in order to determine optimal ROI placement, and computes Ca2+ signal parameters of amplitude, duration and spatial spread. This algorithm was implemented as a freely available plugin for ImageJ (NIH) software. Together with analysis scripts written for the open source statistical processing software R, this approach provides a high-capacity pipeline for performing quick statistical analysis of experimental output. The authors suggest that use of this analysis protocol will lead to a more complete and unbiased characterization of physiologic Ca2+ signaling.

Automated Analysis of Dynamic Ca2+ Signals in Image Sequences

Here a novel region of interest analysis protocol based on sorting best-fit ellipses assigned to regions of positive signal within two-dimensional time lapse image sequences is demonstrated. This algorithm may enable investigators to comprehensively analyze physiological Ca2+ signals with minimal user input and bias.

동적 칼슘의 자동 분석<sup&gt; 2 +</sup이미지 시퀀스에서&gt; 신호

Intracellular Ca2+ signals are commonly studied with fluorescent Ca2+ indicator dyes and microscopy techniques. However, quantitative analysis of Ca2+ ...

siRNA Screening to Identify Ubiquitin and Ubiquitin-like System Regulators of Biological Pathways in Cultured Mammalian Cells

Post-translational modification of proteins with ubiquitin and ubiquitin-like molecules (UBLs) is emerging as a dynamic cellular signaling network that regulates diverse biological pathways including the hypoxia response, proteostasis, the DNA damage response and transcription.&#160; To better understand how UBLs regulate pathways relevant to human disease, we have compiled a human siRNA &#8220;ubiquitome&#8221; library consisting of 1,186 siRNA duplex pools targeting all known and predicted components of UBL system pathways. This library can be screened against a range of cell lines expressing reporters of diverse biological pathways to determine which UBL components act as positive or negative regulators of the pathway in question.&#160; Here, we describe a protocol utilizing this library to identify ubiquitome-regulators of the HIF1A-mediated cellular response to hypoxia using a transcription-based luciferase reporter.&#160; An initial assay development stage is performed to establish suitable screening parameters of the cell line before performing the screen in three stages: primary, secondary and tertiary/deconvolution screening. &#160;The use of targeted over whole genome siRNA libraries is becoming increasingly popular as it offers the advantage of reporting only on members of the pathway with which the investigators are most interested.&#160; Despite inherent limitations of siRNA screening, in particular false-positives caused by siRNA off-target effects, the identification of genuine novel regulators of the pathways in question outweigh these shortcomings, which can be overcome by performing a series of carefully undertaken control experiments.

Here, we describe a methodology to perform a targeted siRNA &#8220;ubiquitome&#8221; screen to identify novel ubiquitin and ubiquitin-like regulators of the HIF1A-mediated cellular response to hypoxia.&#160; This can be adapted to any biological pathway where a robust read out of reporter activity is available.

배양 된 포유 동물 세포의 생물 학적 경로의 유비퀴틴과 유비​​퀴틴 같은 시스템 레귤레이터를 확인하는 siRNA를 상영

Post-translational modification of proteins with ubiquitin and ubiquitin-like molecules (UBLs) is emerging as a dynamic cellular signaling network that ...

Measurement of Heme Synthesis Levels in Mammalian Cells

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. The biosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathy and cancer. This technique uses [4-14C] 5-aminolevulinic acid ([14C] 5-ALA), one of the early precursors in the heme biosynthesis pathway to measure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [14C] 5-ALA followed by extraction of heme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relative levels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis were measured in several mammalian cell lines.

Altered intracellular heme levels are associated with common diseases such as cancer. Thus, there is a need to measure heme biosynthesis levels in diverse cells. The goal of this protocol is to provide a fast and sensitive method to measure and compare the levels of heme synthesis in different cells.

포유 동물 세포에서 헴 합성 레벨 측정

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in ...

Massively Parallel Reporter Assays in Cultured Mammalian Cells

The genetic reporter assay is a well-established and powerful tool for dissecting the relationship between DNA sequences and their gene regulatory activities. The potential throughput of this assay has, however, been limited by the need to individually clone and assay the activity of each sequence on interest using protein fluorescence or enzymatic activity as a proxy for regulatory activity. Advances in high-throughput DNA synthesis and sequencing technologies have recently made it possible to overcome these limitations by multiplexing the construction and interrogation of large libraries of reporter constructs. This protocol describes implementation of a Massively Parallel Reporter Assay (MPRA) that allows direct comparison of hundreds of thousands of putative regulatory sequences in a single cell culture dish.

The genetic reporter assay is a well-established and powerful tool for dissecting the relationship between DNA sequences and their gene regulatory activities. Coupling candidate regulatory elements to reporter genes that carry identifying sequence tags enables massive parallelization of these assays.