从一门课程，已在使用的实验室手册，策划博士HL阿特伍德在多伦多大学动物学系，这些实验进行了修改。这次演习也被用来从制作“ 第 6 次密集IBRO基本神经科学研讨会”，并在1993年（Cooper 等人，1993年），汉城，韩国高丽大学举行的手动修改。目前的修改，需要共同使用的设备到目前在各大学的一天学生定向实验室。肯塔基大学生物系，本科课程和艺术与科学学院办公室支持。

<ol>
	<li>Bennett, M. V. L., Barrio, L. C., Bargiello, T. A., Spray, D. C., Hertzberg, E., Sdez, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gap+junctions:+new+tools,+new+answers,+new+questions.">Gap junctions: new tools, new answers, new questions.</a> Neuron. 6, 305-320 (1991).</li><li>Bernardini, G., Peracchia, C., Peracchia, L. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+effects+of+heptanol+on+gap+junction+structure+and+cell-to-cell+electrical+coupling.">Reversible effects of heptanol on gap junction structure and cell-to-cell electrical coupling.</a> European Journal of Cell Biology. 34 (2), 307-312 (1984).</li><li>Cooper, R. L., Chang, J. J., Ito, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+report+on+the,+"SIXTH+INTENSIVE+IBRO+WORKSHOP+ON+BASIC+NEUROSCIENCE".">A report on the, "SIXTH INTENSIVE IBRO WORKSHOP ON BASIC NEUROSCIENCE".</a> , 116-116 (1985).</li><li>Cragg, B. G., Thomas, P. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+conduction+velocity+and+the+diameter+and+internodal+length+of+peripheral+nerve+fibers..">The relationship between conduction velocity and the diameter and internodal length of peripheral nerve fibers..</a> Journal of Physiology. 136, 606-614 (1957).</li><li>Erlanger, J. G. a. s. s. e. r., S, H., Bishop, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+compound+nature+of+the+action+current+of+nerves+as+disclosed+by+the+cathode+ray+oscillograph.">The compound nature of the action current of nerves as disclosed by the cathode ray oscillograph.</a> American Journal of Physiology. 70, 624-666 (1924).</li><li>Furshpan, E. J., Potter, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transmission+at+the+giant+motor+synapses+of+the+crayfish.">Transmission at the giant motor synapses of the crayfish.</a> Journal of Physiology. 145 (2), 289-325 (1959).</li><li>Johnston, M. F., Simon, S. A., Ramrn, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interaction+of+anesthetics+with+electrical+synapses.">Interaction of anesthetics with electrical synapses.</a> Nature (Lond). 286, 498-500 (1980).</li><li>Loewenstein, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Permeability+of+membrane+junctions.">Permeability of membrane junctions.</a> Annual NY Academy of Sciences. 137, 441-472 (1966).</li><li>Meda, P., Bruzzone, R., Knodel, S., Orci, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blockage+of+cell-to-cell+communication+within+pancreatic+acini+is+associated+with+increased+basal+release+of+amylase.">Blockage of cell-to-cell communication within pancreatic acini is associated with increased basal release of amylase.</a> Journal of Cell Biology. 103 (2), 475-483 (1986).</li><li>Peracchia, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increase+in+gap+junction+resistance+with+acidification+in+crayfish+septate+axons+is+closely+related+to+changes+in+intracellular+calcium+but+not+hydrogen+ion+concentration.">Increase in gap junction resistance with acidification in crayfish septate axons is closely related to changes in intracellular calcium but not hydrogen ion concentration.</a> Journal of Membrane Biology. 113 (1), 75-92 (1990).</li><li>Peracchia, C., Dulhunty, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+resistance+junctions+in+crayfish:+structural+changes+with+functional+uncoupling.">Low resistance junctions in crayfish: structural changes with functional uncoupling.</a> Journal of Cell Biology. 70, 419-439 (1976).</li><li>Peracchia, C., Bernardini, G., Peracchia, L. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+calmodulin+involved+in+the+regulation+of+gap+junction+permeability.">Is calmodulin involved in the regulation of gap junction permeability.</a> Pf&#252;gers Arch. 399, 152-154 (1983).</li><li>Peracchia, C., Lazrak, A., Peracchia, L. L., Peracchia, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+models+of+channel+interaction+and+gating+in+gap+junctions.">Molecular models of channel interaction and gating in gap junctions.</a> Handbook of Membrane Channels. Molecular and Cellular Physiology. , 361-377 (1994).</li><li>Spray, D. C., Harris, A. L., Bennett, M. V. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gap+junctional+conductance+is+a+simple+and+sensitive+function+of+intracellular+pH.">Gap junctional conductance is a simple and sensitive function of intracellular pH.</a> Sciences NY. 211, 712-715 (1981).</li><li>Spray, D. C., Harris, L. L., Bennett, M. V. L., Nuccitelli, R., Deamer, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+pH+and+Ca+dependence+of+gap+junctional+conductance.">Comparison of pH and Ca dependence of gap junctional conductance.</a> Intracellular pH: Its Measurement, Regulation, and Utilization in Cellular Functions. , 445-461 (1982).</li><li>Spray, D. C., White, R., De Carvalho, C., Harris, A. L., Bennett, M. L. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gating+of+gap+junction+channels.">Gating of gap junction channels.</a> Journal of Biophysics. 45, 219-230 (1984).</li><li>Watanabe, A., Grundfest, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impulse+propagation+at+the+septal+and+commissural+junctions+of+crayfish+lateral+giant+axons.">Impulse propagation at the septal and commissural junctions of crayfish lateral giant axons.</a> Journal of General Physiology. 45, 267-308 (1961).</li><li>Wiersma, C. A. G., Hughes, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+functional+anatomy+of+neuronal+units+in+the+abdominal+cord+of+the+crayfish,+Procambarus+clarkii.">On the functional anatomy of neuronal units in the abdominal cord of the crayfish, Procambarus clarkii.</a> Journal of Comparative Neurology. 116, 209-228 (1961).</li></ol>

我们在上线的视频演示，本文的目的是证明细胞的生物物理特性，可以部分，作为电子电路建模。此外，活的神经组织，是比较容易获得，传导速度，不应期和电生理记录技术的基本原则可能与温和的设备投资本科学生实验室。的主题和提出的基本范式，可以很容易地修改为不同课程的要求。 小龙虾和它的丰富的维护，以学生为主导的试验有吸引力的车型。甲壳动物腹神经线一般坚固，并保留最少一个小时的盐水，这是3个小时的学生实验室有足够的生理完整性。 鉴于一些小龙虾的VNC大轴突通过缝隙连接，可以进行额外的实验上所作出的贡献，以及不同的特性，比标准蛙坐骨神经准备发现可证明连接。坐骨神经是一个经典模型，为解决复合动作电位传导性能。它甚至可能是一个有趣的对比实验，让学生比较传导性能，轴突招聘，这两种制剂之间不应期。

电路板 <ol><li>下面列出的实验电路板的实验电子，可在当地的电子产品，如Radio Shack的存储。 </li><li>面包板，电阻，电容，电池和导线，作为实验中的实验电路板的路口。 </li><li>一个共同的电压表（Wavetek Meterman电压表） </li><li> A / D板线录制到计算机。电信号记录到PowerLab/4s接口（ADInstruments，CO，美国科罗拉多州的斯普林斯，）上线。我们使用标准软件名为图表或范围ADInstruments。 </li></ol> 生理学实验 <ol><li>小龙虾（ 克氏螯虾 ）。阿查法拉亚生物供应公司，Raceland，洛杉矶，美国。 </li><li>小龙虾生理盐水（标准）：范Harreveld的解决方案（1936年）修改。 （205毫米）氯化钠氯化钾5.3; 13.5氯化钙2 · 2H 2 O; 2.45氯化镁2 · 6H 2 O 5 HEPES和调整pH至7.4。从Sigma公司（圣路易斯，密苏里州）获得所有生理盐水化学品。 </li><li>解剖工具：精细＃5镊子，精剪，刀刀座，昆虫引脚＃26002-20（所有获得精细科学的工具（美国）公司，373 - G的复古公园径，福斯特市，CA 94404-1139） </li><li>一个神经腔菜（ADInstruments，CO，美国科罗拉多州的斯普林斯，）举行的神经。可用于刺激神经与神经腔菜来的电线。 </li><li>吸电极是用来记录的信号。 </li><li>操纵或钳上环站也将作为持有吸电极。 </li><li>法拉第笼</li><li>解剖显微镜</li><li>高强度照明灯（光源） </li><li>显微镜平台</li><li>差分放大器的AC / DC（AM系统公司型号3000） </li><li> PowerLab系统26T（公元仪器） </li><li>外放大器（公元仪器） </li><li> LabChart 7（ADI仪器） </li><li>解剖工具</li><li> A环的立场和钳作为持有录音吸电极</li></ol>

modeling biological membranes with circuit boards and measuring electrical signals in axons: student laboratory exercises

这是一个示范如何电气模型可以用来描述生物膜。这次演习还介绍了中电使用的生物物理术语。膜模型使用相同的设备在现场准备工作。调查的一个孤立的神经线的一些属性：神经的动作电位，神经元的招聘，和环境因素的反应神经线。

Watch this Scientific Journal Video about Modeling Biological Membranes with Circuit Boards and Measuring Electrical Signals in Axons: Student Laboratory Exercises at JoVE.com

Modeling Biological Membranes with Circuit Boards and Measuring Electrical Signals in Axons: Student Laboratory Exercises

这是一个示范如何使用电气模型，是可以理解的生物膜。我们还演示程序，记录从学生为本的实验室小龙虾的腹神经索的动作电位。

建模生物膜与电路板，并在轴突测量电气信号：学生实验室练习

This is a demonstration of how electrical models can be used to characterize biological membranes. This exercise also introduces biophysical terminology ...

modeling-biological-membranes-with-circuit-boards-measuring

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Basics of Electric Circuits

SCIENTISTS IN ACTION

22.5K 次观看.  University of Kentucky. 这是一个示范如何使用电气模型，是可以理解的生物膜。我们还演示程序，记录从学生为本的实验室小龙虾的腹神经索的动作电位。

视频: Modeling Biological Membranes with Circuit Boards and Measuring Electrical Signals in Axons: Student Laboratory Exercises

Microbial Communities in Nature and Laboratory - Interview

微生物群落，在自然和实验室 - 面试

科研

生物学

Measuring the Induced Membrane Voltage with Di-8-ANEPPS

Placement of a cell into an external electric field causes a local charge redistribution inside and outside of the cell in the vicinity of the cell membrane, resulting in a voltage across the membrane. This voltage, termed the induced membrane voltage (also induced transmembrane voltage, or induced transmembrane potential difference) and denoted by &Delta;&Phi;, exists only as long as the external field is present. If the resting voltage is present on the membrane, the induced voltage superimposes (adds) onto it. By using one of the potentiometric fluorescent dyes, such as di-8-ANEPPS, it is possible to observe the variations of &Delta;&Phi; on the cell membrane and to measure its value noninvasively. di-8-ANEPPS becomes strongly fluorescent when bound to the lipid bilayer of the cell membrane, with the change of the fluorescence intensity proportional to the change of &Delta;&Phi;. This video shows the protocol for measuring &Delta;&Phi; using di-8-ANEPPS and also demonstrates the influence of cell shape on the amplitude and spatial distribution of &Delta;&Phi;.

External electric field induces a voltage on the membrane of a cell, termed the induced membrane voltage (&Delta;&Phi;). By using the potentiometric dye di-8-ANEPPS, it is possible to measure the &Delta;&Phi; noninvasively. This video shows the protocol for measuring &Delta;&Phi; using di-8-ANEPPS.

诱导膜电压测量与DI - 8 - ANEPPS

Placement of a cell into an external electric field causes a local charge redistribution inside and outside of the cell in the vicinity of the cell ...

Computer-assisted Large-scale Visualization and Quantification of Pancreatic Islet Mass, Size Distribution and Architecture

The pancreatic islet is a unique micro-organ composed of several hormone secreting endocrine cells such as beta-cells (insulin), alpha-cells (glucagon), and delta-cells (somatostatin) that are embedded in the exocrine tissues and comprise 1-2% of the entire pancreas. There is a close correlation between body and pancreas weight. Total beta-cell mass also increases proportionately to compensate for the demand for insulin in the body. What escapes this proportionate expansion is the size distribution of islets. Large animals such as humans share similar islet size distributions with mice, suggesting that this micro-organ has a certain size limit to be functional. The inability of large animal pancreata to generate proportionately larger islets is compensated for by an increase in the number of islets and by an increase in the proportion of larger islets in their overall islet size distribution. Furthermore, islets exhibit a striking plasticity in cellular composition and architecture among different species and also within the same species under various pathophysiological conditions. In the present study, we describe novel approaches for the analysis of biological image data in order to facilitate the automation of analytic processes, which allow for the analysis of large and heterogeneous data collections in the study of such dynamic biological processes and complex structures. Such studies have been hampered due to technical difficulties of unbiased sampling and generating large-scale data sets to precisely capture the complexity of biological processes of islet biology. Here we show methods to collect unbiased "representative" data within the limited availability of samples (or to minimize the sample collection) and the standard experimental settings, and to precisely analyze the complex three-dimensional structure of the islet. Computer-assisted automation allows for the collection and analysis of large-scale data sets and also assures unbiased interpretation of the data. Furthermore, the precise quantification of islet size distribution and spatial coordinates (i.e. X, Y, Z-positions) not only leads to an accurate visualization of pancreatic islet structure and composition, but also allows us to identify patterns during development and adaptation to altering conditions through mathematical modeling. The methods developed in this study are applicable to studies of many other systems and organisms as well.

Novel computer-assisted methods of large-scale procurement and analysis of immunohistochemically stained pancreatic specimens are described: (1) Virtual Slice capture of the entire section; (2) Mass analysis of large-scale data; (3) Reconstruction of 2D Virtual Slices; (4) 3D islet mapping; and (5) Mathematical analysis.

计算机辅助大型胰岛质量，粒度分布和结构的可视化和量化

The pancreatic islet is a unique micro-organ composed of several hormone secreting endocrine cells such as beta-cells (insulin), alpha-cells (glucagon), ...

High-throughput Screening and Biosensing with Fluorescent C. elegans Strains

High-throughput screening (HTS) is a powerful approach for identifying chemical modulators of biological processes. However, many compounds identified in screens using cell culture models are often found to be toxic or pharmacologically inactive in vivo1-2. Screening in whole animal models can help avoid these pitfalls and streamline the path to drug development.
C. elegans is a multicellular model organism well suited for HTS. It is small (&lt;1 mm) and can be economically cultured and dispensed in liquids. C. elegans is also one of the most experimentally tractable animal models permitting rapid and detailed identification of drug mode-of-action3.
We describe a protocol for culturing and dispensing fluorescent strains of C. elegans for high-throughput screening of chemical libraries or detection of environmental contaminants that alter the expression of a specific gene. Large numbers of developmentally synchronized worms are grown in liquid culture, harvested, washed, and suspended at a defined density. Worms are then added to black, flat-bottomed 384-well plates using a peristaltic liquid dispenser. Small molecules from a chemical library or test samples (e.g., water, food, or soil) can be added to wells with worms. In vivo, real-time fluorescence intensity is measured with a fluorescence microplate reader. This method can be adapted to any inducible gene in C. elegans for which a suitable reporter is available. Many inducible stress and developmental transcriptional pathways are well defined in C. elegans and GFP transgenic reporter strains already exist for many of them4. When combined with the appropriate transgenic reporters, our method can be used to screen for pathway modulators or to develop robust biosensor assays for environmental contaminants. 
We demonstrate our C. elegans culture and dispensing protocol with an HTS assay we developed to monitor the C. elegans cap &#x2018;n&#x2019; collar transcription factor SKN-1. SKN-1 and its mammalian homologue Nrf2 activate cytoprotective genes during oxidative and xenobiotic stress5-10. Nrf2 protects mammals from numerous age-related disorders such as cancer, neurodegeneration, and chronic inflammation and has become a major chemotherapeutic target11-13.Our assay is based on a GFP transgenic reporter for the SKN-1 target gene gst-414, which encodes a glutathione-s transferase6. The gst-4 reporter is also a biosensor for xenobiotic and oxidative chemicals that activate SKN-1 and can be used to detect low levels of contaminants such as acrylamide and methyl-mercury15-16.

High-throughput Screening and Biosensing with Fluorescent C. elegans Strains

A procedure for liquid-based culturing and dispensing of C. elegans strains expressing fluorescent reporter proteins is described that does not require expensive sorting equipment. This approach can be applied to numerous inducible C. elegans genes for drug discovery or biosensing of contaminants.

高通量筛选和生物传感与荧光 C。线虫菌株

High-throughput screening (HTS) is a powerful approach for identifying chemical modulators of biological processes.  However, many compounds identified in ...

Measuring Fast Calcium Fluxes in Cardiomyocytes

Cardiomyocytes have multiple Ca2+ fluxes of varying duration that work together to optimize function 1,2. Changes in Ca2+ activity in response to extracellular agents is predominantly regulated by the phospholipase C&beta;- G&alpha;q pathway localized on the plasma membrane which is stimulated by agents such as acetylcholine 3,4. We have recently found that plasma membrane protein domains called caveolae5,6 can entrap activated G&alpha;q 7. This entrapment has the effect of stabilizing the activated state of G&alpha;q and resulting in prolonged Ca2+ signals in cardiomyocytes and other cell types8. We uncovered this surprising result by measuring dynamic calcium responses on a fast scale in living cardiomyocytes. Briefly, cells are loaded with a fluorescent Ca2+ indicator. In our studies, we used Ca2+ Green (Invitrogen, Inc.) which exhibits an increase in fluorescence emission intensity upon binding of calcium ions. The fluorescence intensity is then recorded for using a line-scan mode of a laser scanning confocal microscope. This method allows rapid acquisition of the time course of fluorescence intensity in pixels along a selected line, producing several hundreds of time traces on the microsecond time scale. These very fast traces are transferred into excel and then into Sigmaplot for analysis, and are compared to traces obtained for electronic noise, free dye, and other controls. To dissect Ca2+ responses of different flux rates, we performed a histogram analysis that binned pixel intensities with time. Binning allows us to group over 500 traces of scans and visualize the compiled results spatially and temporally on a single plot. Thus, the slow Ca2+ waves that are difficult to discern when the scans are overlaid due to different peak placement and noise, can be readily seen in the binned histograms. Very fast fluxes in the time scale of the measurement show a narrow distribution of intensities in the very short time bins whereas longer Ca2+ waves show binned data with a broad distribution over longer time bins. These different time distributions allow us to dissect the timing of Ca2+fluxes in the cells, and to determine their impact on various cellular events.

We present a method to isolate rapid (microsecond) calcium events from slower fluxes in living cells using laser scanning confocal microscopy. The method measures fluorescence intensity fluctuations of calcium indicators by recording line scans of several hundred pixels in a cell. Histogram analysis allows us to isolate the time scales of different calcium fluxes.

测量心肌细胞的快速钙助焊剂

Cardiomyocytes have multiple Ca2+ fluxes of varying duration that work together to optimize function 1,2. Changes in Ca2+ activity in response to ...

Measuring Spatial and Temporal Ca2+ Signals in Arabidopsis Plants

Developmental and environmental cues induce Ca2+ fluctuations in plant cells. Stimulus-specific spatial-temporal Ca2+ patterns are sensed by cellular Ca2+ binding proteins that initiate Ca2+ signaling cascades. However, we still know little about how stimulus specific Ca2+ signals are generated. The specificity of a Ca2+ signal may be attributed to the sophisticated regulation of the activities of Ca2+ channels and/or transporters in response to a given stimulus. To identify these cellular components and understand their functions, it is crucial to use systems that allow a sensitive and robust recording of Ca2+ signals at both the tissue and cellular levels. Genetically encoded Ca2+ indicators that are targeted to different cellular compartments have provided a platform for live cell confocal imaging of cellular Ca2+ signals. Here we describe instructions for the use of two Ca2+ detection systems: aequorin based FAS (film adhesive seedlings) luminescence Ca2+ imaging and case12 based live cell confocal fluorescence Ca2+ imaging. Luminescence imaging using the FAS system provides a simple, robust and sensitive detection of spatial and temporal Ca2+ signals at the tissue level, while live cell confocal imaging using Case12 provides simultaneous detection of cytosolic and nuclear Ca2+ signals at a high resolution.

Measuring Spatial and Temporal Ca2+ Signals in Arabidopsis Plants

Ca2+ signaling regulates diverse biological processes in plants. Here we present approaches for monitoring abiotic stress induced spatial and temporal Ca2+ signals in Arabidopsis cells and tissues using the genetically encoded Ca2+ indicators Aequorin or Case12.

测量时空的Ca<sup&gt; 2 +</sup&gt;在拟南芥信号

Developmental and environmental cues induce Ca2+ fluctuations in plant cells. Stimulus-specific spatial-temporal Ca2+ patterns are sensed by cellular Ca2+ ...

Measuring Nitrite and Nitrate, Metabolites in the Nitric Oxide Pathway, in Biological Materials using the Chemiluminescence Method

Nitric oxide (NO) is one of the main regulator molecules in vascular homeostasis and also a neurotransmitter. Enzymatically produced NO is oxidized into nitrite and nitrate by interactions with various oxy-heme proteins and other still not well known pathways. The reverse process, reduction of nitrite and nitrate into NO had been discovered in mammals in the last decade and it is gaining attention as one of the possible pathways to either prevent or ease a whole range of cardiovascular, metabolic and muscular disorders that are thought to be associated with decreased levels of NO. It is therefore important to estimate the amount of NO and its metabolites in different body compartments &#8212; blood, body fluids and the various tissues. Blood, due to its easy accessibility, is the preferred compartment used for estimation of NO metabolites. Due to its short lifetime (few milliseconds) and low sub-nanomolar concentration, direct reliable measurements of blood NO in vivo present great technical difficulties. Thus NO availability is usually estimated based on the amount of its oxidation products, nitrite and nitrate. These two metabolites are always measured separately. There are several well established methods to determine their concentrations in biological fluids and tissues. Here we present a protocol for chemiluminescence method (CL), based on spectrophotometrical detection of NO after nitrite or nitrate reduction by tri-iodide or vanadium(III) chloride solutions, respectively. The sensitivity for nitrite and nitrate detection is in low nanomolar range, which sets CL as the most sensitive method currently available to determine changes in NO metabolic pathways. We explain in detail how to prepare samples from biological fluids and tissues in order to preserve original amounts of nitrite and nitrate present at the time of collection and how to determine their respective amounts in samples. Limitations of the CL technique are also explained.

Nitric oxide (NO) is an important signaling molecule in vascular homeostasis. NO production in vivo is too low for direct measurement. Chemiluminescence provides useful insight into NO cycle via measuring its precursors and oxidation products, nitrite and nitrate. Nitrite / nitrate determination in body tissues and fluids is explained.

用化学发光法测定硝酸盐和亚硝酸盐，代谢产物中的一氧化氮途径，在生物材料

Nitric oxide (NO) is one of the main regulator molecules in vascular homeostasis and also a neurotransmitter. Enzymatically produced NO is oxidized into ...

Cultivation of Caenorhabditis elegans in Three Dimensions in the Laboratory

The use of genetic model organisms such as Caenorhabditis elegans has led to seminal discoveries in biology over the last five decades. Most of what we know about C. elegans is limited to laboratory cultivation of the nematodes that may not necessarily reflect the environments they normally inhabit in nature. Cultivation of C. elegans in a 3D habitat that is more similar to the 3D matrix that worms encounter in rotten fruits and vegetative compost in nature could reveal novel phenotypes and behaviors not observed in 2D. In addition, experiments in 3D can address how phenotypes we observe in 2D are relevant for the worm in nature. Here, a new method in which C. elegans grows and reproduces normally in three dimensions is presented. Cultivation of C. elegans in Nematode Growth Tube-3D (NGT-3D) can allow us to measure the reproductive fitness of C. elegans strains or different conditions in a 3D environment. We also present a novel method, termed Nematode Growth Bottle-3D (NGB-3D), to cultivate C. elegans in 3D for microscopic analysis. These methods allow scientists to study C. elegans biology in conditions that are more reflective of the environments they encounter in nature. These can help us to understand the overlying evolutionary relevance of the physiology and behavior of C. elegans we observe in the laboratory.

Cultivation of Caenorhabditis elegans in Three Dimensions in the Laboratory

We present a simple method to construct 3D nematode cultivation systems called NGT-3D and NGB-3D. These can be used to study nematode fitness and behaviors in habitats that are more similar to natural Caenorhabditis elegans habitats than the standard 2D laboratory C. elegans culture plates.

栽培<em&gt;秀丽隐杆线虫</em&gt;在三个维度实验室

The use of genetic model organisms such as Caenorhabditis elegans has led to seminal discoveries in biology over the last five decades. Most of what we ...

Measuring Crop Motility and Food Passaging in Drosophila

Most animals use the gastrointestinal (GI) tract to digest food. The movement of the ingested food in the GI tract is essential for nutrient absorption. Disordered GI motility and gastric emptying cause multiple diseases and symptoms. As a powerful genetic model organism, Drosophila can be used in GI motility research. The Drosophila crop is an organ that contracts and moves food into the midgut for further digestion, functionally similar to a mammalian stomach. Presented is a protocol to study Drosophila crop motility using simple measurement tools. A method for counting crop contractions to evaluate crop motility and a method for detecting the distribution of food dyed blue between the crop and gut using a spectrophotometer to investigate the effect of the crop on food passaging is described. The method was used to detect the difference in crop motility between control and nprl2 mutant flies. This protocol is both cost-efficient and highly sensitive to crop motility.

Measuring Crop Motility and Food Passaging in Drosophila

The goal of this protocol is to measure crop contraction and quantify food distribution in the Drosophila gut.

测量果蝇的作物运动性和食物通度

Most animals use the gastrointestinal (GI) tract to digest food. The movement of the ingested food in the GI tract is essential for nutrient absorption. ...

Tethered Bilayer Lipid Membranes to Monitor Heat Transfer between Gold Nanoparticles and Lipid Membranes

Here we report a protocol to investigate the heat transfer between irradiated gold nanoparticles (GNPs) and bilayer lipid membranes by electrochemistry using tethered bilayer lipid membranes (tBLMs) assembled on gold electrodes. Irradiated modified GNPs, such as streptavidin-conjugated GNPs, are embedded in tBLMs containing target molecules, such as biotin. By using this approach, the heat transfer processes between irradiated GNPs and model bilayer lipid membrane with entities of interest are mediated by a horizontally focused laser beam. The thermal predictive computational model is used to confirm the electrochemically induced conductance changes in the tBLMs. Under the specific conditions used, detecting heat pulses required specific attachment of the gold nanoparticles to the membrane surface, while unbound gold nanoparticles failed to elicit a measurable response. This technique serves as a powerful detection biosensor which can be directly utilized for the design and development of strategies for thermal therapies that permits optimization of the laser parameters, particle size, particle coatings and composition.

This work outlines a protocol to achieve dynamic, non-invasive monitoring of heat transfer from laser-irradiated gold nanoparticles to tBLMs. The system combines impedance spectroscopy for the real-time measurement of conductance changes across the tBLMs, with a horizontally focused laser beam that drives gold nanoparticle illumination, for heat production.

系绳双层脂膜，以监测金纳米粒子和脂膜之间的热传递

Here we report a protocol to investigate the heat transfer between irradiated gold nanoparticles (GNPs) and bilayer lipid membranes by electrochemistry ...