이 작품은 NIH 연구 부여, 간질 재단 교부금 및 맥나이트 재단 교부금 Drosophila 과일 파리에서 MT 실험에 UC 버클리 동물 사용위원회 명시된 지침과 규정에 따라 수행되었다 지원했다.

표본 준비 : 실험이 있기 전날 밤에, 원하는 유전자형의 남성 파리 anesthetized과 부드러운 나일론 플러그와 유리병에 넣습니다. 커튼 볼도 작동합니다. anesthetization 다음, 발작 임계값이 변경되어 밤 이상적이다하지만 이상, 파리가 가장 최소한 6 시간 동안 남아 있습니다 있도록. 실험 당일, 파리 한쪽에 치과 왁스의 레이어와 유리 슬라이드에 한 번에 하나씩 장착하고 있습니다. 하나의 비행은 진공 라인에 연결된 23 게이지 바늘 (자르는 날카로운 팁 포함)를 사용하여 머리에 의해 포착됩니다. 비행은 다음 왁스로 다리와 날개를 추진하여 슬라이드에있는 왁스에 부착된입니다. 파리가 고정되면 왁스는 목에까지 밀고 있으며, 눈이 완전히 머리를 고정합니다. 전기 생리학 : 지금 장착하고 출발 준비를 전기 생리학에 배치됩니다 파리는 설정. 전기 생리학 세트 최대 micromanipulators 세 세트, 부착이 날카롭게 텅스텐 전극 하나 각각 구성되어 있습니다. 전압은 자극 전극에 부착된 격리 장치에 연결된 자극기에 의해 제공됩니다. 기록 전극은 차례로 디지털 스토리지 오실로 스코프에 첨부되어 사전에 A에 연결되어 있습니다. 그것이 필수 아니지만, 그것은 응답 청취 만들 수 있도록 오실로 스코프에 매여 있고 스피커를 가지고 유용합니다. 접지 전극은 비행의 복부에 삽입됩니다. 기록 전극은 비행의 흉부에 도설 세로 근육의 하나에 삽입됩니다. 자극 전극은 머리에 삽입됩니다. 각각의 눈쪽으로 하나. 각 펄스 사이 이초과 연속 펄스 간격 : 자극기는 다음과 같은 설정을 시작해야한다. 맥박이 지연이 없어야합니다. 펄스 폭 0.2ms해야합니다. 오실로 스코프는 저장 기능이 설정되어 있고 다음 설정을해야 : 시간 ​​/ DIV는 1ms/DIV로 설정해야합니다. 볼트 / DIV는 0.1V/DIV 50 MV / DIV 중 하나에 설정되어야합니다. 거대한 섬유 임계값은 단일 펄스를 제공하고 답변을 얻을하는 데 필요한 최소 전압을 지적 의해 결정됩니다. 이 전압이 주위에 일반적으로 V. 거대한 섬유 임계값이 결정되면, 파리를 pulsing 중지하고 오실로 스코프의 설정을 변경 : 0.2 S / DIV 자극기의 설정을 변경해야합니다 : 펄스 간격은 단일로 설정해야합니다. 기차가 켜져 3 초로 설정해야합니다. 파형 매개 변수는 다음과 같습니다 300 MS에 대한 200Hz에서 0.5 MS 펄스. 전압은 원하는 설정 및 비행의 뇌에 전달 펄스의 고주파 기차로 변경됩니다. 발작이 유발되지 않은 경우 오실로 스코프 추적 기차 후 평평한 라인을 표시합니다. 설정이 신속하게 다시 시작하는 설정으로 설정하는 경우, 하나의 펄스가 거대한 섬유 시스템에 응답을 발생합니다. 발작이 유발되는 경우, 오실로 스코프 기차 후 발작과 같은 활동을 표시합니다. 설정이 빠르게 원래 설정으로 전환하는 경우, 하나의 펄스가 거대한 섬유 시스템에 응답을 활성화 실패합니다. 파리 활동과 같은 발작이 유발되지 않을 수있는 고주파 자극 wavetrain 후 불응기 있습니다. 더 발작이 발생하지 않으면 파리가 약 7 분 동안 내화물입니다. 발작이 유발되는 경우, 파리 약 17분의 불응기 있습니다. 임계값 결정하거나 때까지 거대한 섬유 반응보고 너무 약해 될 때까지 임계값을 결정하면, 추가 고주파 자극은 같은 날 (내화물 기간 동안 적절한 시간 후)에 전달할 수 있습니다. 실험이 완료되면, 즉시이 전기 생리학에서 제거 설정, 왁스에서 출시하고, 처분이다.

<ol>
	<li>Kuebler, D., Tanouye, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modifications+of+seizure+susceptibility+in+Drosophila.">Modifications of seizure susceptibility in Drosophila.</a> J Neurophysiol. 83, 998-1009 (2000).</li><li>Kuebler, D., Zhang, H., Ren, X., Tanouye, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+suppression+of+seizure+susceptibility+in+Drosophila.">Genetic suppression of seizure susceptibility in Drosophila.</a> J Neurophysiol. 86, 1211-1225 (2001).</li><li>Song, J., Tanouye, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seizure+suppression+by+shakB2,+a+gap+junction+mutation+in+Drosophila.">Seizure suppression by shakB2, a gap junction mutation in Drosophila.</a> J Neurophysiol. 95, 627-635 (2006).</li></ol>

이 비디오는 개별 Drosophila의 비행의 발작 임계값을 결정하는 기본 단계를 보여주었다. 대신 디지털 오실로 스코프를 사용, 컴퓨터 디지타이저도 사용할 수 있습니다. 이 기술은 파리의 발작 직전에 약물이나 유전자 변경의 효과를 결정하는 데 유용합니다.

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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Digital oscilloscope</td>
<td>&nbsp;</td>
<td>Hitachi</td>
<td>VC-6523</td>
<td>&nbsp;</td>
<tr>
<td>Stimulator</td>
<td>&nbsp;</td>
<td>Cornerstone</td>
<td>S-900</td>
<td>&nbsp;</td>
<tr>
<td>Preamplifier</td>
<td>&nbsp;</td>
<td>World Precision Instruments</td>
<td>Electro 705</td>
<td>&nbsp;</td>
<tr>
<td>Micromanipulators</td>
<td>&nbsp;</td>
<td>Narishige</td>
<td>various</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

neurocircuit assays for seizures in epilepsy mutants of drosophila

Drosophila melanogaster은 활동과 같은 발작을 공부를위한 유용한 도구입니다. 발작이 물리적 충격이나 전기 자극을 통해 유도하거나 수있는 돌연변이의 다양한 발작 활동과 행동의 다양한 측면의 연구에 사용할 수 있습니다. 있을만큼 충분히 높은 전압에서 자극하면 야생 형을 포함한 모든 비행은, 압수와 같은 활동을 받아야합니다. 활동과 같은 발작 모든 - 또는 - 아무것도 응답하고 각각의 유전자형은 특정 발작 한계가 있습니다. 비행의 특정 유전자형의 발작 임계값은 약물 치료 또는 유전자 억제 또는 개선을 통해 변경할 수 있습니다. 임계값은 쉽게 전기 생리학에 의해 측정됩니다. 활동 같은 발작은 뇌에 직접 전달 및 흉부에있는 등 지느러미 근육 길이 (DLMs)를 통해 기록된 고주파 전기 자극을 통해 유도하실 수 있습니다. DLMs은 거대한 섬유 시스템의 일부에 의해 innervated 있습니다. 저전압, 고주파 자극과 함께 시작하고, 이후 작은 단위로 전압을 높여, 하나의 비행에 대한 발작 임계값을 측정할 수 있습니다.

Watch this Scientific Journal Video about Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila at JoVE.com

Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila

고주파 전기 자극 압수와 같은 활동을 사용하는 것은에서 유도된 수 있습니다<em&gt; Drosophila</em&gt;. 이 활동은 쉽게 거대한 섬유 시스템에서 기록됩니다.

의 간질 발작의 돌연변이에 대한 Neurocircuit의 Assays Drosophila</em

Drosophila melanogaster is a useful tool for studying seizure like activity. A variety of mutants in which seizures can be induced through either physical ...

neurocircuit-assays-for-seizures-in-epilepsy-mutants-of-drosophila

Research

JoVE Journal

Biology

Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila

10.4K 조회수.  University of California, Berkeley. 고주파 전기 자극 압수와 같은 활동을 사용하는 것은에서 유도된 수 있습니다 Drosophila. 이 활동은 쉽게 거대한 섬유 시스템에서 기록됩니다.

비디오: Neurocircuit Assays for Seizures in Epilepsy Mutants of Drosophila

Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the anatomy and connectivity of its nervous system has been determined from electron micrographs and refined by pharmacological assays. In this video, we describe how two complementary neural stimulants, an acetylcholinesterase inhibitor, called aldicarb, and a gamma-aminobutyric acid (GABA) receptor antagonist, called pentylenetetrazole (PTZ), may be employed to specifically characterize signaling at C. elegans neuromuscular junctions (NMJs) and facilitate our understanding of antagonistic neural circuits.
Of 302 C. elegans neurons, nineteen GABAergic D-type motor neurons innervate body wall muscles (BWMs), while four GABAergic neurons, called RMEs, innervate head muscles. Conversely, thirty-nine motor neurons express the excitatory neurotransmitter, acetylcholine (ACh), and antagonize GABA transmission at BWMs to coordinate locomotion. The antagonistic nature of GABAergic and cholinergic motor neurons at body wall NMJs was initially determined by laser ablation and later buttressed by aldicarb exposure. Acute aldicarb exposure results in a time-course or dose-responsive paralysis in wild-type worms. Yet, loss of excitatory ACh transmission confers resistance to aldicarb, as less ACh accumulates at worm NMJs, leading to less stimulation of BWMs. Resistance to aldicarb may be observed with ACh-specific or general synaptic function mutants. Consistent with antagonistic GABA and ACh transmission, loss of GABA transmission, or a failure to negatively regulate ACh release, confers hypersensitivity to aldicarb. Although aldicarb exposure has led to the isolation of numerous worm homologs of neurotransmission genes, aldicarb exposure alone cannot efficiently determine prevailing roles for genes and pathways in specific C. elegans motor neurons. For this purpose, we have introduced a complementary experimental approach, which uses PTZ.
Neurotransmission mutants display clear phenotypes, distinct from aldicarb-induced paralysis, in response to PTZ. Wild-type worms, as well as mutants with specific inabilities to release or receive ACh, do not show apparent sensitivity to PTZ. However, GABA mutants, as well as general synaptic function mutants, display anterior convulsions in a time-course or dose-responsive manner. Mutants that cannot negatively regulate general neurotransmitter release and, thus, secrete excessive amounts of ACh onto BWMs, become paralyzed on PTZ. The PTZ-induced phenotypes of discrete mutant classes indicate that a complementary approach with aldicarb and PTZ exposure paradigms in C. elegans may accelerate our understanding of neurotransmission. Moreover, videos demonstrating how we perform pharmacological assays should establish consistent methods for C. elegans research.

This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures.

C. 엘레간스 시냅틱 전송 돌연변이의 약리 특성에 대한 패러다임

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the ...

연구

생물학

Lens Transplantation in Zebrafish and its Application in the Analysis of Eye Mutants

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development can be addressed. The zebrafish is useful for genetic studies due to several advantageous characteristics, including small size, high fecundity, short lifecycle, and ease of care. Lens development occurs rapidly in zebrafish. By 72 hpf, the zebrafish lens is functionally mature [3]. Abundant genetic and molecular resources are available to support research in zebrafish. In addition, the similarity of the zebrafish eye to those of other vertebrates provides basis for its use as an excellent animal model of human defects[4-7]. Several zebrafish mutants exhibit lens abnormalities, including high levels of cell death, which in some cases leads to a complete degeneration of lens tissues [8]. To determine whether lens abnormalities are due to intrinsic causes or to defective interactions with the surrounding tissues, transplantation of a mutant lens into a wild-type eye is performed. Using fire-polished metal needles, mutant or wild-type lenses are carefully dissected from the donor animal, and transferred into the host. To distinguish wild-type and mutant tissues, a transgenic line is used as the donor. This line expresses membrane-bound GFP in all tissues, including the lens. This transplantation technique is an essential tool in the studies of zebrafish lens mutants.

Lens development involves interactions with other tissues. Several zebrafish eye mutants are characterized by an abnormally small lens size. Here we demonstrate a lens transplantation experiment to determine whether this phenotype is due to intrinsic causes or defective interactions with tissues that surround the lens.

렌즈 Zebrafish의 이식과 눈 돌연변이의 분석에의 응용

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development ...

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

The morphogenesis of the Drosophila embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell shape changes during embryonic development. One of the challenges faced in studying this structure is that the lumen of the heart tube, as well as the membrane features that are crucial to heart tube formation, are difficult to visualize in whole mount embryos, due to the small size of the heart tube and intra-lumenal space relative to the embryo. The use of transmission electron microscopy allows for higher magnification of these structures and gives the advantage of examining the embryos in cross section, which easily reveals the size and shape of the lumen. In this video, we detail the process for reliable fixation, embedding, and sectioning of late stage Drosophila embryos in order to visualize the heart tube lumen as well as important cellular structures including cell-cell junctions and the basement membrane.

Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube

We describe a process for fixation, embedding, sectioning, and imaging of late stage Drosophila embryos for Trasmission Electron Microscopy of the embryonic heart tube. This technique allows for the visualization of the heart tube lumen as well as the basement membrane, which lines the lumen of the heart.

의 전자 현미경을위한 배아의 준비 Drosophila 태아의 심장 관

The morphogenesis of the Drosophila  embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell ...

Analysis of Schwann-astrocyte Interactions Using In Vitro Assays

Schwann cells are one of the commonly used cells in repair strategies following spinal cord injuries. Schwann cells are capable of supporting axonal regeneration and sprouting by secreting growth factors 1,2 and providing growth promoting adhesion molecules 3 and extracellular matrix molecules 4. In addition they myelinate the demyelinated axons at the site of injury 5.
However following transplantation, Schwann cells do not migrate from the site of implant and do not intermingle with the host astrocytes 6,7. This results in formation of a sharp boundary between the Schwann cells and astrocytes, creating an obstacle for growing axons trying to exit the graft back into the host tissue proximally and distally. Astrocytes in contact with Schwann cells also undergo hypertrophy and up-regulate the inhibitory molecules 8-13.
In vitro assays have been used to model Schwann cell-astrocyte interactions and have been important in understanding the mechanism underlying the cellular behaviour.
These in vitro assays include boundary assay, where a co-culture is made using two different cells with each cell type occupying different territories with only a small gap separating the two cell fronts. As the cells divide and migrate, the two cellular fronts get closer to each other and finally collide. This allows the behaviour of the two cellular populations to be analyzed at the boundary. Another variation of the same technique is to mix the two cellular populations in culture and over time the two cell types segregate with Schwann cells clumped together as islands in between astrocytes together creating multiple Schwann-astrocyte boundaries.
The second assay used in studying the interaction of two cell types is the migration assay where cellular movement can be tracked on the surface of the other cell type monolayer 14,15. This assay is commonly known as inverted coverslip assay. Schwann cells are cultured on small glass fragments and they are inverted face down onto the surface of astrocyte monolayers and migration is assessed from the edge of coverslip.
Both assays have been instrumental in studying the underlying mechanisms involved in the cellular exclusion and boundary formation. Some of the molecules identified using these techniques include N-Cadherins 15, Chondroitin Sulphate proteoglycans(CSPGs) 16,17, FGF/Heparin 18, Eph/Ephrins19.
This article intends to describe boundary assay and migration assay in stepwise fashion and elucidate the possible technical problems that might occur.

Analysis of Schwann-astrocyte Interactions Using In Vitro Assays

This article intends to describe in stepwise fashion the commonly used in vitro assays used in studying Schwann cell-asrtocyte interactions.

사용 Schwann - astrocyte 상호 작용 분석 체외에서 Assays

Schwann cells are one of the commonly used cells in repair strategies following spinal cord injuries. Schwann cells are capable of supporting axonal ...

Endurance Training Protocol and Longitudinal Performance Assays for Drosophila melanogaster

One of the most pressing problems facing modern medical researchers is the surging levels of obesity, with the consequent increase in associated disorders such as diabetes and cardiovascular disease 1-3. An important topic of research into these associated health problems involves the role of endurance exercise as a beneficial intervention.
Exercise training is an inexpensive, non-invasive intervention with several beneficial results, including reduction in excess body fat 4, increased insulin sensitivity in skeletal muscle 5, increased anti-inflammatory and antioxidative responses 6, and improved contractile capacity in cardiomyocytes 7. Low intensity exercise is known to increase mitochondrial activity and biogenesis in humans 8 and mice, with the transcriptional coactivator PGC1-&alpha; as an important intermediate 9,10. 
Despite the importance of exercise as a tool for combating several important age-related diseases, extensive longitudinal genetic studies have been impeded by the lack of an endurance training protocol for a short-lived genetic model species. The variety of genetic tools available for use with Drosophila, together with its short lifespan and inexpensive maintenance, make it an appealing model for further study of these genetic mechanisms. With this in mind we have developed a novel apparatus, known as the Power Tower, for large scale exercise-training in Drosophila melanogaster 11. The Power Tower utilizes the flies' instinctive negative geotaxis behavior to repetitively induce rapid climbing. Each time the machine lifts, then drops, the platform of flies, the flies are induced to climb. Flies continue to respond as long as the machine is in operation or until they become too fatigued to respond. Thus, the researcher can use this machine to provide simultaneous training to large numbers of age-matched and genetically identical flies. Additionally, we describe associated assays useful to track longitudinal progress of fly cohorts during training.

Endurance Training Protocol and Longitudinal Performance Assays for Drosophila melanogaster

We describe the first endurance training protocol for an important genetic model species, Drosophila melanogaster, and outline several assays to chart improvements in mobility following training.

Drosophila melanogaster를위한 지구력 훈련 프로토콜과 세로 성능 Assays

One of the most pressing problems facing modern medical researchers is the surging levels of obesity, with the consequent increase in associated disorders ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

사멸 세포 간극의 이미지를하는 동안 라이브<em&gt; 초파리</em&gt; 배아

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must be maintained to avoid deleterious consequences 1. External or internal factors that disrupt this balance can lead to protein aggregation, toxicity and cell death. In humans this is a major contributing factor to the symptoms associated with neurodegenerative disorders such as Huntington's, Parkinson's, and Alzheimer's diseases 10. It is therefore essential that the proteins involved in maintenance of proteostasis be identified in order to develop treatments for these debilitating diseases. This article describes techniques for monitoring in vivo protein folding at near-real time resolution using the model protein firefly luciferase fused to green fluorescent protein (FFL-GFP). FFL-GFP is a unique model chimeric protein as the FFL moiety is extremely sensitive to stress-induced misfolding and aggregation, which inactivates the enzyme 12. Luciferase activity is monitored using an enzymatic assay, and the GFP moiety provides a method of visualizing soluble or aggregated FFL using automated microscopy. These coupled methods incorporate two parallel and technically independent approaches to analyze both refolding and functional reactivation of an enzyme after stress. Activity recovery can be directly correlated with kinetics of disaggregation and re-solubilization to better understand how protein quality control factors such as protein chaperones collaborate to perform these functions. In addition, gene deletions or mutations can be used to test contributions of specific proteins or protein subunits to this process. In this article we examine the contributions of the protein disaggregase Hsp104 13, known to partner with the Hsp40/70/nucleotide exchange factor (NEF) refolding system 5, to protein refolding to validate this approach.

Coupled Assays for Monitoring Protein Refolding in Saccharomyces cerevisiae

This article describes the use of a firefly luciferase-GFP fusion protein to investigate in vivo protein folding in Saccharomyces cerevisiae. Using this reagent, refolding of a model heat-denatured protein can be monitored simultaneously by fluorescence microscopy and an enzymatic assay to probe the roles of proteostasis network components in protein quality control.

의 모니터링 단백질 접힘에 대한 결합 분석 실험<em&gt; 사카 cerevisiae의</em

Proteostasis, defined as the combined processes of protein folding/biogenesis, refolding/repair, and degradation, is a delicate cellular balance that must ...

Viability Assays for Cells in Culture

Manual cell counts on a microscope are a sensitive means of assessing cellular viability but are time-consuming and therefore expensive. Computerized viability assays are expensive in terms of equipment but can be faster and more objective than manual cell counts. The present report describes the use of three such viability assays. Two of these assays are infrared and one is luminescent. Both infrared assays rely on a 16&#160;bit Odyssey Imager. One infrared assay uses the DRAQ5 stain for nuclei combined with the Sapphire stain for cytosol and is visualized in the 700 nm channel. The other infrared assay, an In-Cell Western, uses antibodies against cytoskeletal proteins (&#945;-tubulin or microtubule associated protein 2) and labels them in the 800 nm channel. The third viability assay is a commonly used luminescent assay for ATP, but we use a quarter of the recommended volume to save on cost. These measurements are all linear and correlate with the number of cells plated, but vary in sensitivity. All three assays circumvent time-consuming microscopy and sample the entire well, thereby reducing sampling error. Finally, all of the assays can easily be completed within one day of the end of the experiment, allowing greater numbers of experiments to be performed within short timeframes. However, they all rely on the assumption that cell numbers remain in proportion to signal strength after treatments, an assumption that is sometimes not met, especially for cellular ATP. Furthermore, if cells increase or decrease in size after treatment, this might affect signal strength without affecting cell number. We conclude that all viability assays, including manual counts, suffer from a number of caveats, but that computerized viability assays are well worth the initial investment. Using all three assays together yields a comprehensive view of cellular structure and function.

Therapeutic compounds are often first examined in vitro with viability assays. Blind cell counts by a human observer can be highly sensitive to small changes in cell number but do not assess function. Computerized viability assays, as described here, can assess both structure and function in an objective manner.

문화의 세포에 대한 생존 분석 실험

Manual cell counts on a microscope are a sensitive means of assessing cellular viability but are time-consuming and therefore expensive. Computerized ...

A Method of Permeabilization of Drosophila Embryos for Assays of Small Molecule Activity

The Drosophila embryo has long been a powerful laboratory model for elucidating molecular and genetic mechanisms that control development. The ease of genetic manipulations with this model has supplanted pharmacological approaches that are commonplace in other animal models and cell-based assays. Here we describe recent advances in a protocol that enables application of small molecules to the developing fruit fly embryo. The method details steps to overcome the impermeability of the eggshell while maintaining embryo viability. Eggshell permeabilization across a broad range of developmental stages is achieved by application of a previously described d-limonene embryo permeabilization solvent (EPS1) and by aging embryos at reduced temperature (18 &#176;C) prior to treatments. In addition, use of a far-red dye (CY5) as a permeabilization indicator is described, which is compatible with downstream applications involving standard red and green fluorescent dyes in live and fixed preparations. This protocol is applicable to studies using bioactive compounds to probe developmental mechanisms as well as for studies aimed at evaluating teratogenic or pharmacologic activity of uncharacterized small molecules.

A Method of Permeabilization of Drosophila Embryos for Assays of Small Molecule Activity

Introduction of small molecules to the developing Drosophila embryo offers great potential for characterizing biological activity of novel compounds, drugs, and toxins as well as for probing fundamental developmental pathways. Methods described herein outline steps that overcome natural barriers to this approach, expanding the utility of the Drosophila embryo model.

의 Permeabilization의 방법<em&gt; 초파리</em작은 분자 활동의 분석 실험을위한&gt; 태아

The Drosophila embryo has long been a powerful laboratory model for elucidating molecular and genetic mechanisms that control development. The ease of ...

Generation of Marked and Markerless Mutants in Model Cyanobacterial Species

Cyanobacteria are ecologically important organisms and potential platforms for production of biofuels and useful industrial products. Genetic manipulation of cyanobacteria, especially model organisms such as Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002, is a key tool for both basic and applied research. Generation of unmarked mutants, whereby chromosomal alterations are introduced into a strain via insertion of an antibiotic resistance cassette (a manipulatable fragment of DNA containing one or more genes), followed by subsequent removal of this cassette using a negative selectable marker, is a particularly powerful technique. Unmarked mutants can be repeatedly genetically manipulated, allowing as many alterations to be introduced into a strain as desired. In addition, the absence of genes encoding antibiotic resistance proteins in the mutated strain is desirable, as it avoids the possibility of 'escape' of antibiotic resistant organisms into the environment. However, detailed methods for repeated rounds of genetic manipulation of cyanobacteria are not well described in the scientific literature. Here we provide a comprehensive description of this technique, which we have successfully used to generate mutants with multiple deletions, single point mutations within a gene of interest and insertion of novel gene cassettes.

Introducing multiple genomic alterations into cyanobacteria is an essential tool in the development of strains for industrial and basic research purposes. We describe a system for generating unmarked mutants in the model cyanobacterial species Synechocystis sp. PCC6803 and marked mutants in Synechococcus sp. PCC7002.

모델 시아 노 박테리아 종의 표시 및 Markerless 돌연변이의 생성

Cyanobacteria are ecologically important organisms and potential platforms for production of biofuels and useful industrial products. Genetic manipulation ...