Name: a rapid and chemical-free hemoglobin assay with photothermal angular light scattering
Uploaded: 2016-12-07T15:00:00.000+00:00
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Description: Watch this Scientific Journal Video about A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering at JoVE.com

This research was supported by the research programs of the National Research Foundation of Korea (NRF) (NRF-2015R1A1A1A05001548 and NRF-2015R1A5A1037668).

与血液样本实验是在遵守有关法律和机构指导进行。的样品已被获取并在该机构的临床试验处理剩余血样。 1. PT-AS光学装置注意:一个可以利用一个空微毛细管用于初始的PT-AS的设置。 <ol><li>装入一个空的微毛细管具有分别为200和330微米，内径和外径，和大于约5厘米的毛细管夹具的长度。市售的纤维夹具可被用作管夹具。 </li><li>安全锚650nm的激光指示器， 即探测光源，照亮毛细管。探测光束应该比毛细管大。将毛细管垂帘听政（ 如白皮书），观察的角度周期性模式。 </li><li>对于检测部分，删除任何镜头摄像头可以直接捕捉scatt化工e圈格局。在相对于探测光束方向25-35度的一个角度的毛细管后面的网络摄像头位置。确保由毛细管产生的角度周期性图案可与检测器（ 图1）来测量。观察的角度周期性图案在图像传感器的中间时，图像传感器被正确地定位。 </li><li>一个532纳米PT激发光源来照亮毛细管位置。在PT光源在任何角度，只要该PT激励光与毛细管探测光束重叠，不直接到达探测器的位置。采用高光功率通常血样PT激发改善对PT-AS的灵敏度，因为它会导致在对RI更大的变化。 <ol><li>使用采用PT激发光源的最高光功率。此外，确保在PT激励光重叠在毛细管的探测光。使用PT激发光的光束尺寸的至少两倍的探测光来加热整个探头体积。 </li></ol></li><li>放置一个长通滤波器在探测器的前面以阻止532纳米的光，并测量仅650纳米探测光。 </li><li>照明毛细管之前安装在PT激发光的路径的光学菜刀。光学斩波器被用来调节该PT激发光强度。 </li></ol> 2.血液样品制备<ol><li>绘制的6ml新鲜全血中贫血状况入乙二胺四乙酸血液采样管，并充分混合样品井。不需要其他处理。 </li><li>使用提取的24小时内PT-AS传感器，以防止凝血测量血液样本。 </li></ol> 3. PT-AS测量协议<ol><li>加载一个微毛细管与血液样品以测量。通过将管进入血液个饱通过毛细作用血液毛细管充足。测定所需的最小样品体积由毛细管的内径和探测光束大小决定。 <ol><li>采用管的200微米的内径。探测光束尺寸为2mm中的代表性结果，这表明该测量可以与&gt; 63 NL的样本量来进行。 </li></ol></li><li>装入毛细管在夹具的指定位置。 </li><li>打开650纳米探针激光照射血装载微毛细管。角周期性图案应与摄像头观察到。 </li><li>打开532纳米的PT激发激光照亮管。 </li><li>运行的光斩波器调制以2Hz该PT激发光的强度。 注:此操作条件的选择的理由讨论和Kim 等人说明。 12。 <ol><li>在光学斩波器的马达头组件安装斩光轮系统。 </li><li>打开斩波控制箱，并使用该控制旋钮在控制台设定调制频率。 </li><li>通过运行控制旋钮菜刀。 </li></ol></li><li>记录通过在MPEG-4（MP4）格式的摄像头，持续5秒的波动散射图案。 </li></ol> 4.信号处理注:PT-AS的信号处理被使用实验室开发的MATLAB代码执行。 <ol><li>加载视频文件中提取图像。对于每个图像[参见图2（a）为一代表图像]，由沿垂直方向的计算的像素值的平均值获得平均散射图案[ 图2（B，C）。 </li><li>评估的傅立叶变换平均散射图案，并且在峰值空间频率计算的相位。所有录制的图像的所有帧执行这些操作。 </li><li>利用所有图像获得的相位值，绘制时间相位波动〔 如图2（d）]。注意，相位波动在该PT调制频率。取傅立叶在调制频率变换在时域的相位变动的，并且得到的幅度。此信号被称为对PT-AS信号〔 如图2（E）]。 </li><li>由它的PT-AS信号转换成测量血液样品中的[血红蛋白]使用在协议5中获得的校正曲线相应的[血红蛋白。 </li></ol> 5. PT-AS校准<ol><li>制备血液样品中，具有[血红蛋白]被均匀地分布在PT-AS传感器的检测范围内的值（ 例如 ，0 - 29克/分升）。 </li><li>校准之前，量化使用参考血液分析仪的样品的[血红蛋白]值。测量样品的PT-AS信号。 </li><li>通过派生进行线性最小二乘法拟合有关[血红蛋白]将PT-AS信号的校正曲线，[血红蛋白] = A [PT-AS信号] + B，该experimenta的升的结果。对于表1中指定的操作条件，间[血红蛋白]和PT-AS信号的关系被认为是[血红蛋白] = 5.13 [PT-AS信号] - 0.09。利用MATLAB代码来执行的线性拟合。 </li></ol>

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No conflict of interest is declared.

在PT-AS传感器表示能够未处理的血液样本的直接[血红蛋白]测量的全光学方法。的方法，使用在红细胞的血红蛋白分子的内在的PT响应量化[血红蛋白]血液中。下通过532纳米的光照射，血红蛋白分子吸收的光的能量，并产生热量。所得温升改变血样的RI。 BSI的高灵敏度RI被利用来测量血液中这种RI变化。先前，我们表明，在PT-AS传感器使[血红蛋白]测量0.12克/分升以上0.35-17.9克/分升，这与在市场上的商...

验血通常以评估整体的人类健康和检测与某些疾病生物标志物。例如，在血液中的胆固醇浓度用作用于高脂血症的标准，这是密切相关的心血管疾病和胰腺炎。血糖含量应经常测量，如葡萄糖水平与并发症如糖尿病酮症酸中毒和高血糖高渗综合征。严重的疾病，如疟疾，人类免疫缺陷病毒和获得性免疫缺陷综合征是由血液检查确诊，和血液成分，包括红细胞，血小板的量化和白细胞使胰腺和肾脏疾病筛查。 血红蛋白，血的关键组成部分，构成了红细胞的约96％，并输送氧气到人体器官。其质量浓度显著改变（[血红蛋白]）可能表明我tabolic变化，肝胆疾病，和神经，心血管及内分泌紊乱1。 [血红蛋白]因此在常规验血测量。尤其是贫血患者，透析患者和孕妇强烈建议监察[血红蛋白]作为一个重要的任务2。 各种[血红蛋白]检测方法就这样被开发。血红蛋白氰化法，对于[血红蛋白]量化最常用的技术之一，使用氰化钾（KCN）摧毁红细胞3的脂质双层。通过在540nm附近的化学展品高吸收产生的氰化物血红蛋白;因此，[血红蛋白]测量值可以通过比色分析进行。这种方法由于其简单性广泛采用，但所采用的化学品（ 如 ，KCN和dimethyllaurylamine氧化物）是有毒的对人体和环境。血细胞比容方案测量与总血液体积的红血细胞的体积比乌梅通过离心分离;然而，它需要一个相对大的血液量（50-100微升）4。分光光度法测量方法[血红蛋白]正是没有任何的化学物质，但在多个波长和大血容量测量需要5,6。同样，用于测量[血红蛋白]几种光学方法已经提出了包括基于光散射的检测方法，但其测量精度上的理论血模型的准确度在很大程度上取决于。 为了克服这些限制，基于血红蛋白的光热（PT）作用[血红蛋白]检测方法近来已经提出7。血红蛋白，它是由主要是铁的氧化物，在532纳米吸收光的光能量转换成热8-10。这个PT温度增加可以光学地通过测量血液样品的折光指数（RI）的变化来检测。 Yim 等。就业谱域光学相干reflectometry以测量在含有血液室11在PT光路长度变化。虽然该方法能够化学 - 自由和直接[血红蛋白]测定，使用分光计和干涉装置可阻碍其小型化。我们最近提出一种替代[血红蛋白]检测方法，称为光热角光散射（PT-AS）的传感器，它更适合于设备的小型化12。在PT-AS传感器利用了背散射干涉（BSI）的高RI灵敏度测量毛细管内的血液样品的RI PT变化。 BSI已用来测量各种解决方案13-15中RI和监测在自由溶液16生物化学相互作用。该PT-AS传感器采用类似的光学结构为BSI，但结合光热激发的设置来测量血液样本中的RI PT增加。在BSI和PT-AS传感器的工作原理进行了详细的描述别处<sup&gt; 12,15。 PT-AS传感器表现出高灵敏度[血红蛋白]测量在很宽的检测范围（0.35-17.9克/分升），并能够与&lt;100 NL的样品体积运行。血液试样的无预处理是必需的，并且在测量时间仅为〜5秒。在这里，实验装置和详细的测量协议进行说明。使用血液样品从贫血患者提供代表的PT-AS的结果，其结果对那些从血液分析仪比较，以评估对PT-AS传感器的精度。

<table><tbody><tr><td>650 nm laser pointer</td><td>LASMAC</td><td>LED-1</td><td>Probe light</td></tr><tr><td>Hollow round glass capillaries</td><td>VitroCom</td><td>CV2033</td><td>Blood sample container</td></tr><tr><td>Webcam</td><td>Logitech</td><td>C525</td><td>CMOS optical sensor</td></tr><tr><td>Optical chopper system</td><td>Thorlabs</td><td>MC2000-EC</td><td>Optical chopper</td></tr><tr><td>Plastic long-pass filter</td><td>Edmund Optics</td><td>#43-942</td><td>To reject 532-nm PT excitation light</td></tr><tr><td>Fiber clamp</td><td>Thorlabs</td><td>SM1F1-250</td><td>Capillary tube fixture</td></tr><tr><td>EDTA coated blood sampling tube</td><td>Greiner Bio-One</td><td>VACUETTE 454217</td><td>Blood sampling &amp;amp; anticoagulating</td></tr><tr><td>Hematology analyzer</td><td>Siemens AG</td><td>ADVIA 2120i</td><td>Reference hematology analyzer</td></tr></tbody></table>

a rapid and chemical-free hemoglobin assay with photothermal angular light scattering

光热角光散射（PT-AS）是用于测量血液样本的血红蛋白浓度（[血红蛋白]）一种新颖的光学方法。对血红蛋白分子的固有光热响应的基础上，该传感器可实现高灵敏度，[血红蛋白]的无化学计量。 [血红蛋白] 0.12克/分升以上0.35的范围内的极限检测能力 - 17.9克/ dl的先前已证实。该方法可容易地使用便宜的消费电子设备，诸如激光指示器和网络摄像头实现。作为血液容器使用微毛细管还使用纳升规模的血容量和低运行成本的血红蛋白测定。这里，对于对PT-AS光学设置和信号处理程序的详细说明介绍。实验方案和用于贫血的条件血样代表性的结果（[血红蛋白] = 5.3，7.5，和9.9克/分升）也提供，并测量与这些往复相比马血液分析仪。其在实施和操作简单应使其广泛应用在临床实验室和资源有限的环境。

使用PT-AS传感器被执行的血红蛋白测定法，其测量结果与那些从血细胞分析仪进行了比较。实验用1.4瓦/厘米2，2赫兹的PT调制频率，并测量5秒的时间的一个PT激励光强度进行的。 表1总结了实验条件。探针和PT激发光的光束尺寸分别为5.5和2毫米。摄像头以30 fps的帧速率录制的影像。测量中，采用了三种不同的Hb浓度的贫血的血液样本。在PT-AS测量之前，?...

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A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering

A photo-thermal angular light scattering (PT-AS) sensor enables the rapid and chemical-free hemoglobin assay of nanoliter-scale blood samples. Here, details of the PT-AS setup and a measurement protocol for the hemoglobin concentration in blood are provided. Representative results for anemic blood samples are also presented.

一种快速和无农药血红蛋白检测法与光热角光散射

Photo-thermal angular light scattering (PT-AS) is a novel optical method for measuring the hemoglobin concentration ([Hb]) of blood samples. On the basis ...

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JoVE Journal

Bioengineering

9.6K 次观看.  Yonsei University. A photo-thermal angular light scattering (PT-AS) sensor enables the rapid and chemical-free hemoglobin assay of nanoliter-scale blood samples. Here, details of the PT-AS setup and a measurement protocol for the hemoglobin concentration in blood are provided. Representative results for anemic blood samples are also presented.

视频: A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering

Antigens Protected Functional Red Blood Cells By The Membrane Grafting Of Compact Hyperbranched Polyglycerols

Red blood cell (RBC) transfusion is vital for the treatment of a number of acute and chronic medical problems such as thalassemia major and sickle cell anemia 1-3. Due to the presence of multitude of antigens on the RBC surface (~308 known antigens 4), patients in the chronic blood transfusion therapy develop alloantibodies due to the miss match of minor antigens on transfused RBCs 4, 5. Grafting of hydrophilic polymers such as polyethylene glycol (PEG) and hyperbranched polyglycerol (HPG) forms an exclusion layer on RBC membrane that prevents the interaction of antibodies with surface antigens without affecting the passage of small molecules such as oxygen ,glucose, and ions3. At present no method is available for the generation of universal red blood donor cells in part because of the daunting challenge presented by the presence of large number of antigens (protein and carbohydrate based) on the RBC surface and the development of such methods will significantly improve transfusion safety, and dramatically improve the availability and use of RBCs. In this report, the experiments that are used to develop antigen protected functional RBCs by the membrane grafting of HPG and their characterization are presented. HPGs are highly biocompatible compact polymers 6, 7, and are expected to be located within the cell glycocalyx that surrounds the lipid membrane 8, 9 and mask RBC surface antigens10, 11.

The cell membrane modification of red blood cells (RBCs) with hyperbranched polyglycerol (HPG) is presented. Modified RBCs were characterized by aqueous two phase partitioning, osmotic fragility and complement mediated lysis. The camouflage of surface proteins and antigens was evaluated using the flow cytometry and Micro Typing System (MTS) blood phenotyping cards.

紧凑型超支化聚乙二醇接枝的膜抗原受保护的功能性红血细胞

Red blood cell (RBC) transfusion is vital for the treatment of a number of acute and chronic medical problems such as thalassemia major and sickle cell ...

科研

免疫与感染

A Rhodopsin Transport Assay by High-Content Imaging Analysis

Rhodopsin misfolding mutations lead to rod photoreceptor death that is manifested as autosomal dominant retinitis pigmentosa (RP), a progressive blinding disease that lacks effective treatment. We hypothesize that the cytotoxicity of the misfolded rhodopsin mutant can be alleviated by pharmacologically stabilizing the mutant rhodopsin protein. The P23H mutation, among the other Class II rhodopsin mutations, encodes a structurally unstable rhodopsin mutant protein that is accumulated in the endoplasmic reticulum (ER), whereas the wild type rhodopsin is transported to the plasma membrane in mammalian cells. We previously performed a luminescence-based high-throughput screen (HTS) and identified a group of pharmacological chaperones that rescued the transport of the P23H rhodopsin from ER to the plasma membrane. Here, using an immunostaining method followed by a high-content imaging analysis, we quantified the mutant rhodopsin protein amount in the whole cell and on the plasma membrane. This method is informative and effective to identify true hits from false positives following HTS. Additionally, the high-content image analysis enabled us to quantify multiple parameters from a single experiment to evaluate the pharmacological properties of each compound. Using this assay, we analyzed the effect of 11 different compounds towards six RP associated rhodopsin mutants, obtaining a 2-D pharmacological profile for a quantitative and qualitative understanding about the structural stability of these rhodopsin mutants and efficacy of different compounds towards these mutants.

Here, we described a high-content imaging method to quantify the transport of rhodopsin mutants associated with retinitis pigmentosa. A multiple-wavelength scoring analysis was used to quantify rhodopsin protein on the cell surface or in the whole cell.

高含量成像分析研究。

Rhodopsin misfolding mutations lead to rod photoreceptor death that is manifested as autosomal dominant retinitis pigmentosa (RP), a progressive blinding ...

化学

Rapid Determination of Antibody-Antigen Affinity by Mass Photometry

Measurements of the specificity and affinity of antigen-antibody interactions are critically important for medical and research applications. In this protocol, we describe the implementation of a new single-molecule technique, mass photometry (MP), for this purpose. MP is a label- and immobilization-free technique that detects and quantifies molecular masses and populations of antibodies and antigen-antibody complexes on a single-molecule level. MP analyzes the antigen-antibody sample within minutes, allowing for the precise determination of the binding affinity and simultaneously providing information on the stoichiometry and the oligomeric state of the proteins. This is a simple and straightforward technique that requires only picomole quantities of protein and no expensive consumables. The same procedure can be used to study protein-protein binding for proteins with a molecular mass larger than 50 kDa. For multivalent protein interactions, the affinities of multiple binding sites can be obtained in a single measurement. However, the single-molecule mode of measurement and the lack of labeling imposes some experimental limitations. This method gives the best results when applied to measurements of sub-micromolar interaction affinities, antigens with a molecular mass of 20 kDa or larger, and relatively pure protein samples. We also describe the procedure for performing the required fitting and calculation steps using basic data analysis software.

We describe a single-molecule approach to antigen-antibody affinity measurements using mass photometry (MP). The MP-based protocol is fast, accurate, uses a very small amount of material, and does not require protein modification.

通过质量光度法快速测定抗体抗原亲和力

Measurements of the specificity and affinity of antigen-antibody interactions are critically important for medical and research applications. In this ...

生物化学

Time-resolved F&#246;rster Resonance Energy Transfer Assays for Measurement of Endogenous Phosphorylated STAT Proteins in Human Cells

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway plays a crucial role in mediating cellular responses to cytokines and growth factors. STAT proteins are activated by tyrosine phosphorylation mediated mainly by JAKs. The abnormal activation of STAT signaling pathways is implicated in many human diseases, especially cancer and immune-related conditions. Therefore, the ability to monitor STAT protein phosphorylation within the native cell signaling environment is important for both academic and drug discovery research. The traditional assay formats available to quantify phosphorylated STAT proteins include western blotting and the enzyme-linked immunosorbent assay (ELISA). These heterogeneous methods are labor-intensive, low-throughput, and often not reliable (specific) in the case of western blotting. Homogeneous (no-wash) methods are available but remain expensive. 
Here, detailed protocols are provided for the sensitive, robust, and cost-effective measurement in a 384-well format of endogenous levels of phosphorylated STAT1 (Y701), STAT3 (Y705), STAT4 (Y693), STAT5 (Y694/Y699), and STAT6 (Y641) in cell lysates from adherent or suspension cells using the novel THUNDER time-resolved F&#246;rster resonance energy transfer (TR-FRET) platform. The workflow for the cellular assay is simple, fast, and designed for high-throughput screening (HTS). The assay protocol is flexible, uses a low-volume sample (15 &#181;L), requires only one reagent addition step, and can be adapted to low-throughput and high-throughput applications. Each phospho-STAT sandwich immunoassay is validated under optimized conditions with known agonists and inhibitors and generates the expected pharmacology and Z'-factor values. As TR-FRET assays are ratiometric and require no washing steps, they provide much better reproducibility than traditional approaches. Together, this suite of assays provides new cost-effective tools for a more comprehensive analysis of specific phosphorylated STAT proteins following cell treatment and the screening and characterization of specific and selective modulators of the JAK/STAT signaling pathway.

Time-resolved F&#246;rster resonance energy transfer cell-based assay protocols are described for the simple, specific, sensitive, and robust quantification of endogenous phosphorylated signal transducer and activator of transcription (STAT) 1/3/4/5/6 proteins in cell lysates in a 384-well format.

时间分辨Förster共振能量转移测定法，用于测量人细胞中的内源性磷酸化STAT蛋白

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway plays a crucial role in mediating cellular responses to ...

Magnetic Levitation Coupled with Portable Imaging and Analysis for Disease Diagnostics

Currently, many clinical diagnostic procedures are complex, costly, inefficient, and inaccessible to a large population in the world. The requirements for specialized equipment and trained personnel require that many diagnostic tests be performed at remote, centralized clinical laboratories. Magnetic levitation is a simple yet powerful technique and can be applied to levitate cells, which are suspended in a paramagnetic solution and placed in a magnetic field, at a position determined by equilibrium between a magnetic force and a buoyancy force. Here, we present a versatile platform technology designed for point-of-care diagnostics which uses magnetic levitation coupled to microscopic imaging and automated analysis to determine the density distribution of a patient's cells as a useful diagnostic indicator. We present two platforms operating on this principle: (i) a smartphone-compatible version of the technology, where the built-in smartphone camera is used to image cells in the magnetic field and a smartphone application processes the images and to measures the density distribution of the cells and (ii) a self-contained version where a camera board is used to capture images and an embedded processing unit with attached thin-film-transistor (TFT) screen measures and displays the results. Demonstrated applications include: (i) measuring the altered distribution of a cell population with a disease phenotype compared to a healthy phenotype, which is applied to sickle cell disease diagnosis, and (ii) separation of different cell types based on their characteristic densities, which is applied to separate white blood cells from red blood cells for white blood cell cytometry. These applications, as well as future extensions of the essential density-based measurements enabled by this portable, user-friendly platform technology, will significantly enhance disease diagnostic capabilities at the point of care.

We present a magnetic levitation technique coupled with automated imaging and analysis in both a smartphone-compatible device and a device with embedded imaging and processing. This is applied to measure the density distribution of cells with two demonstrated biomedical applications: sickle cell disease diagnosis and separating white and red blood cells.

磁悬浮加上便携式成像与分析诊断疾病

Currently, many clinical diagnostic procedures are complex, costly, inefficient, and inaccessible to a large population in the world. The requirements for ...

生物工程

Rapid Homogeneous Detection of Biological Assays Using Magnetic Modulation Biosensing System

A magnetic modulation biosensing system (MMB) [1,2] rapidly and homogeneously detected biological targets at low concentrations without any washing or separation step. When the IL-8 target was present, a 'sandwich'-based assay attached magnetic beads with IL-8 capture antibody to streptavidin coupled fluorescent protein via the IL-8 target and a biotinylated IL-8 antibody. The magnetic beads are maneuvered into oscillatory motion by applying an alternating magnetic field gradient through two electromagnetic poles. The fluorescent proteins, which are attached to the magnetic beads are condensed into the detection area and their movement in and out of an orthogonal laser beam produces a periodic fluorescent signal that is demodulated using synchronous detection. The magnetic modulation biosensing system was previously used to detect the coding sequences of the non-structural Ibaraki virus protein 3 (NS3) complementary DNA (cDNA) [2]. The techniques that are demonstrated in this work for external manipulation and condensation of particles may be used for other applications, e.g. delivery of magnetically-coupled drugs in-vivo or enhancing the contrast for in-vivo imaging applications.

Magnetic modulation biosensing system is utilized to rapidly, sensitively and simply detect biological assays, such as DNA molecules and proteins.

利用磁调制生物传感系统的生物检测的快速均质检测

A magnetic modulation biosensing system (MMB) [1,2] rapidly and homogeneously detected biological targets at low concentrations without any washing or ...

生物学

Simultaneous Evaluation of Cerebral Hemodynamics and Light Scattering Properties of the In Vivo Rat Brain Using Multispectral Diffuse Reflectance Imaging

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional multispectral diffuse reflectance imaging system. This system is constructed from a broadband white light source, a motorized filter wheel with a set of narrowband interference filters, a light guide, a collecting lens, a video zoom lens, and a monochromatic charged-coupled device (CCD) camera. An ellipsoidal cranial window is made in the skull bone of a rat under isoflurane anesthesia to capture in vivo multispectral diffuse reflectance images of the cortical surface. Regulation of the fraction of inspired oxygen using a gas mixture device enables the induction of different respiratory states such as normoxia, hyperoxia, and anoxia. A Monte Carlo simulation-based multiple regression analysis for the measured multispectral diffuse reflectance images at nine wavelengths (500, 520, 540, 560, 570, 580, 600, 730, and 760 nm) is then performed to visualize the two-dimensional maps of hemodynamics and the light scattering properties of the in vivo rat brain.

Simultaneous Evaluation of Cerebral Hemodynamics and Light Scattering Properties of the In Vivo Rat Brain Using Multispectral Diffuse Reflectance Imaging

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional multispectral diffuse reflectance imaging system.

脑血流动力学和的光散射特性的同步评估<em&gt;体内</em&gt;大鼠脑使用多光谱漫反射成像

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional ...

神经科学

A Precision Medicine Tool for Measurement and Monitoring of Hemoglobin S in Sickle Cell Disease Patients Receiving Transfusion Therapy

Sickle cell disease (SCD) causes many severe health complications, including anemia, stroke, and acute chest syndrome. Red blood cell transfusion is the most commonly used therapy to treat or prevent these devastating complications. Other therapies include hydroxyurea therapy as well as bone marrow transplantation. Chronic intermittent transfusion is especially indicated to prevent recurrent strokes. However, transfusion therapy is associated with significant adverse effects (e.g., alloimmunization and iron overload). The point-of-care (POC) lateral flow immunoassay used here quantifies the %HbS in 15 min using a small patient blood sample. Utilizing this information, the healthcare provider is able to adjust blood transfusion volume for SCD patients to achieve the desired target HbS (most often &#60;30%), while reducing the risk of transfusion-related complications. When compared to laboratory hemoglobin electrophoresis data for 38 whole blood samples, the POC test performed with very high correlation and linear fit (slope = 0.9949, R2 = 0.9751). The strong agreement between the two hemoglobin S percentage (%HbS) quantifying methods shows that 89.5% of samples fall within &#177;5.2% HbS bias. The calibration for quantifying %HbS is built into the device to allow for an automated quantification of %HbS. This time- and cost-effective POC test thus allows the healthcare provider to make timely informed decisions when treating SCD patients, using accurate and updated data.

We have developed a point-of-care immunoassay to rapidly quantify hemoglobin S (HbS) levels during transfusion therapy for sickle cell disease (SCD) patients. By applying a small amount of treated blood to the device, the healthcare provider can determine the %HbS in a SCD patient to immediately inform clinical decisions.

Sickle cell disease (SCD) causes many severe health complications, including anemia, stroke, and acute chest syndrome. Red blood cell transfusion is the ...

医学

Homogeneous Time-resolved F&#246;rster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion

The detection of insulin secretion is critical for elucidating mechanisms of regulated secretion as well as in studies of metabolism. Though numerous insulin assays have existed for decades, the recent advent of homogeneous time-resolved F&#246;rster Resonance Energy Transfer (HTRF) technology has significantly simplified these measurements. This is a rapid, cost-effective, reproducible, and robust optical assay reliant upon antibodies conjugated to bright fluorophores with long lasting emission which facilitates time-resolved F&#246;rster Resonance Energy Transfer. Moreover, HTRF insulin detection is amenable for the development of high-throughput screening assays. Here we use HTRF to detect insulin secretion in INS-1E cells, a rat insulinoma-derived cell line. This allows us to estimate basal levels of insulin and their changes in response to glucose stimulation. In addition, we use this insulin detection system to confirm the role of dopamine as a negative regulator of glucose-stimulated insulin secretion (GSIS). In a similar manner, other dopamine D2-like receptor agonists, quinpirole, and bromocriptine, reduce GSIS in a concentration-dependent manner. Our results highlight the utility of the HTRF insulin assay format in determining the role of numerous drugs in GSIS and their pharmacological profiles.

Here, we present homogeneous time resolved FRET (HTRF) as an efficient method for rapid detection of insulin secreted from cells.

均匀时间分辨 Förster 共振能量转移法检测胰岛素分泌

The detection of insulin secretion is critical for elucidating mechanisms of regulated secretion as well as in studies of metabolism. Though numerous ...

<meta charset="utf8"></head><body>优化生物分子的 VIS-SWIR 光谱

Characterization of Biological Absorption Spectra Spanning the Visible to the Short-Wave Infrared

For noninvasive light-based physiological monitoring, optimal wavelengths of individual tissue components can be identified using absorption spectroscopy. However, because of the lack of sensitivity of hardware at longer wavelengths, absorption spectroscopy has typically been applied for wavelengths in the visible (VIS) and near-infrared (NIR) range from 400 to 1,000 nm. Hardware advancements in the short-wave infrared (SWIR) range have enabled investigators to explore wavelengths in the ~1,000 nm to 3,000 nm range in which fall characteristic absorption peaks for lipid, protein, and water. These molecules are difficult to visualize in the VIS-NIR and can provide label-free sources of biological contrast. Furthermore, lower SWIR absorption has been observed for melanin, the primary chromophore responsible for skin pigmentation. In vivo&#160;optical devices like clinically standard pulse oximeters have been found to have reduced accuracy in people with darkly pigmented skin, possibly because of the stronger melanin absorption in the VIS range. Thus, error associated with skin pigmentation could be reduced by using devices operating in the SWIR. Optical instrument design is facilitated by the understanding of the absorption properties of core tissue components from the VIS to the SWIR range. This article describes protocols and instrumentation for obtaining VIS-SWIR absorption spectra of common tissue absorbers: oxygenated hemoglobin, deoxygenated hemoglobin, melanin, water, and lipid.

<meta charset="utf8"></head><body>从可见光到短波红外的生物吸收光谱的表征

Biological samples have distinct optical characteristics in the short-wave infrared (SWIR) compared to the visible (VIS) and near-infrared (NIR) wavelength ranges. However, recording pure SWIR absorption spectra is challenging and rarely conducted for biological molecules. This article presents a method to characterize the VIS-SWIR absorption spectra of biological absorbers.

从可见光到短波红外的生物吸收光谱的表征

For noninvasive light-based physiological monitoring, optimal wavelengths of individual tissue components can be identified using absorption spectroscopy. ...