This work was supported by the European Research Council (ERC Starting Grant n&#956;LIPIDS, No. 203428) and ETH Zurich (project number: ETH-49 12-2). The authors of this manuscript would like to thank Bodo Hattendorf for help with the ICP-MS and F. Kurth for cell counting. The authors also would like to thank Christoph B&#228;rtschi and Roland M&#228;der for their support with building the mechanical setup. The clean room facility FIRST at ETH Zurich is acknowledged for support in microfabrication.

1. SU-8主控制作（图2） 注:在一个干净的房间，以防止由于灰尘颗粒缺陷执行的SU-8母模的制造。都需要的制造中，一个晶片与微流体特征和一个没有两个晶片。 <ol><li>准备主模具的微流控芯片。首先施加粘合层的硅晶片。 <ol><li>脱水的硅晶片在200℃下10分钟。向下冷却晶片至RT，并用下面的协议将其加载到一个旋涂器和旋涂用的SU-8 2002。 </li><li>分配约3ml抗蚀到晶片上。 </li><li>旋转晶片以500rpm进行10秒，以分散在抗蚀剂在整个晶片。 </li><li>旋转晶片以2000rpm进行30秒，达到大约2微米的抗蚀剂的高度。 </li></ol></li><li>删除从用丙酮浸泡过的拭子的晶片的边缘多余的抗蚀剂，以防止晶片粘附到热板中的下一个步骤。烘烤晶片60秒，在95℃的热板上。 </li><li>露出晶片的整个用紫外光（80毫焦/厘米2，在365纳米）。后烘焙晶片120秒至95℃。 </li><li>冷却该晶片向下，并立即使用以下协议的SU-8 2050再次旋涂在晶片: <ol><li>旋转晶片以100rpm进行20秒（分配在该步骤期间约3ml的SU-8抗蚀剂）。 </li><li>旋转晶片以500rpm进行10秒，以分散在抗蚀剂在整个晶片。 </li><li>旋转晶片在3250转，30秒产生的大约40微米的抗蚀剂厚度。 </li></ol></li><li>再次，去除用丙酮浸泡拭子和软烘烤的热板上进行180秒的晶片的晶片在65℃的边缘，为360秒，在95℃下过量抗拒。 </li><li>准备通过光掩膜STI它CKING到钠钙玻璃。参见图3为掩膜设计。使用掩模对准以暴露抗蚀剂的紫外线（160毫焦耳/厘米2，在365nm下测得）通过制备面膜。再次烘烤暴露的晶片上的热板上进行60秒，在65℃和360秒，在95℃。 </li><li>晶片冷却至室温后，浸泡在一个玻璃培养皿填充有显影剂5分钟来开发抵抗。轻轻摇动培养皿中，除去未曝光的SU-8。冲洗晶圆异丙醇和吹干燥，氮气枪。 </li><li>检查在显微镜下的晶片。万一未显影抗蚀遗体上的功能，又开发晶片几分钟，如在步骤1.7中所述。 </li><li>通过烘烤晶片2小时，在200℃除去任何残余的溶剂。检查的功能，高度与台阶仪。在的情况下测得的高度不同于所述期望高度开始与该原再次山坳并且在步骤1.1.4适应的转速。 </li><li>防止PDMS到晶片的粘附通过用50μl1 1H，1H，2H，2H -perfluorodecyltrichlorosilane的将其放置在干燥器一起在一个小瓷盘silanize它。减少在干燥器中的压力为100毫巴和孵化晶片12小时。 <ol><li>为空白的PDMS份silanize使用步骤1.10的方法的另一硅晶片。为了节省时间silanize两晶片同时在一个单一的干燥器。 </li></ol></li></ol> 2. LADE芯片制造注:拉德芯片是由那些通过粘接24粘接 ​​在一起的两个的PDMS片出来。第一部分包含了微流控功能。另一部分则是平坦的，并用于密封所述通道。结合在一起时，它们形成所必需的圆形状的接口与液滴运输系统的芯片。这里，在制造两部分，并测试其粘合进行说明。所有的处理步骤示于图4中 。 <ol><li>制备44克PDMS的混合40克预聚物与4克固化剂的PDMS（这将导致在高达6芯片）。脱气PDMS在干燥器中，直到它是无气泡（这将需要约20分钟）。 </li><li>结构化半的副本成型。 <ol><li>将铸造的形式于晶片顶部和周围使用设计的指导结构咬合到位（ 见图5）。跳过捕捉到地方平PDMS减半。 </li><li>倾大约3到脱气的PDMS为4g在铸造形式，并放置6分钟的热板上在150℃。降温在铸造的形式固化PDMS小心地提起用抹刀铸造形式晶圆。 </li><li>为了防止该微流体通道的任何污染覆盖，这是以前在接触无线芯片的侧TH用胶带的晶片。小心切割沿的PDMS部分的边缘上的胶带，以除去过量的PDMS。 </li></ol></li><li>以制造平坦PDMS半部重复上述步骤2.2.1至2.2.3与空白硅烷化晶片。 </li><li>胶带剥离和冲流体连接孔与活检冲床的结构化半。保护用胶带结构储存过程中。 </li><li>通过使用固化剂24的PDMS粘接粘结PDMS部分组合在一起。 <ol><li>就拿未经处理的硅片上，旋涂用PDMS固化剂30秒在6000转。取晶片出的旋涂机的。 </li><li>从结构化半取出磁带，并把它们与向下面临到晶圆的结构。轻轻推了PDMS的顶部以去除气泡。 </li><li>从空白PDMS半取下胶带。取从晶片结构化减半，并手动对齐的平坦PDMS减半的顶部。轻轻挤压分一同以除去气泡并让组装芯片固化24小时在RT。不要用力的部位推到一起，因为这可能会导致渠道崩溃。 </li></ol></li><li>切割沿标志线正交用美工刀，打开出口喷嘴的喷嘴通道中的芯片的前端。使用一个对准装置，以确保一个直的切口，这是必要的直喷液。检查显微镜在微流体通道和灰尘颗粒缺陷下的芯片。放的磁带上的进气孔存储过程中保护芯片。 </li><li>一个缓冲瓶与管路连接到一个干燥氮气源和到拉德芯片的所有入口。存50微升1 1H，1H，2H，2H -perfluorodecyltrichlorosilane在缓冲瓶的底部，并关闭它。 </li><li>通过冲洗所有通道20分钟用携带1 1H，1H氮气流Silanize微流体通道</em&gt;，2 小时，在大约为1毫升/秒的流速2小时-perfluorodecyltrichlorosilane。该芯片已准备好用于实验和可以存储在至少几个星期在RT。 </li></ol> 3.准备测量/液滴运输系统注:建立整个液滴运输系统上的光学表的顶部，由于必须构造一个稳定的支撑结构的安装。整个液滴运输系统的方案， 如图6所示。 <ol><li>安装自定义气旋聚（甲基丙烯酸甲酯）（PMMA）的适配器附不锈钢管垂直地一个50厘米。附加适配器氦源与质量流量控制器。附加（高速）相机和灯适配器上的另一网站的液滴可视化。 </li><li>放置一个盒式加热器，在钢管的中部，并使用聚（氯乙烯）（PVC）管和一个可利管连接器连接到钢管的端部与膜desolvator的入口连接。 </li><li>连接desolvator的出口与另一个PVC管，以层流适配器，它被直接连接到所述ICPMS入口。层流适配器连接到氩源与质量流量控制器和以后用它来掺和氩以实现稳定的运转状态。 </li><li>对齐适配器以及钢管垂直用水平。如果定位不准确，就有可能导致液滴显著的损失。插入插头插入适配器，以防止气体泄漏系统预热时间期间。 </li><li>启动所有上述气体流和使用中的设置，从表1中的设备。允许系统预热15分钟。墨盒加热器需要2个小时，温度稳定，就提前开机。 </li><li>放置在机架上的注射泵在旋风氦适配器的高度。守之间的距离注射器泵和所述适配器尽可能短。 </li></ol> 4.测量注意:下面的协议被写入，因为可以使用各种溶液和悬浮液的一般术语。然而，细胞悬浮液，应稀释到&lt;1×10 7个细胞/ ml，当进行单细胞分析，其浓度，以确保大部分液滴仅携带一个小区。用于与细胞的测量将注射器泵以一定的角度，使得所述注射器的出口点向下和安装管道中，它们指向向下的方式。 <ol><li>连接管的注射器。负载25毫升注射器用全氟己烷和1 1ml注射器与样品溶液或悬浮液。删除被困在注射器和管所有的泡沫。 </li><li>在注射泵安装注射器，并把它们连接到该芯片的入口。使用从一开始就设置启动注射泵表1（或更高的流速）。给流3到5分钟，以稳定。 <ol><li>从与组织的芯片的端部除去过量的液体。液体现在应该从芯片在一条直线喷气弹出。如果一个直的喷射不能由用纸巾擦拭来实现更换芯片并重新开始此步骤。 </li></ol></li><li>从适配器拔下插头，并小心地将芯片插入适配器。润滑与FC-40，如果有必要的芯片。的芯片可用于在至少2小时的实验。 </li><li>改变流速为从表1中的推荐的测量设置范围内。所述PFH更低流量不仅节省PFH而且还降低了信号的背景下，所造成的等压干扰。 </li><li>给系统2-5分钟，以稳定（取决于所选择的流速）。优化ICPMS感兴趣的分析物的信号强度最高。 <ol><li>先后调整所有的克流在质量流量控制器ASES（参照表1中的推荐范围），直到所关注的分析物的最大信号强度来实现的。调等离子体功率和聚焦透镜的电压（根据制造商建议的范围）上以同样的方式的ICPMS。 </li></ol></li><li>设置ICPMS至10毫秒的停留时间（适用于所使用的非常ICPMS，但可以与其他仪器进行调整，以保证一个时间分辨获取）。开始记录使用制造商的协议特定的M / Z的信号。 </li><li>在测量后，传送原始数据到数据分析程序进行评估。仓中的数据，每10毫秒中的计数定，具有一个内置的功能，并积所得对数仓中心值。配合一个高斯函数的标绘频率分布直方图的每个峰。均值和拟合的西格玛代表平均值的信号强度及其标准偏差，分别。 </li></ol> &lt;P类="j​​ove_title"&gt; 5。校准概念<ol><li>测含有所述元素或感兴趣的同时流速为样本元素的单层或多层元件标准溶液。 </li><li>放置拉德芯片中在显微镜培养皿。为了更好的图像质量，请使用一个非圆的芯片。制造该芯片如在步骤2中所述，但使用的部分圆形一个简单的矩形铸造形式代替。 </li><li>按照步骤4.1到4.2.1启动液滴产生。设置流率以在步骤5.1中使用的流速。 </li><li>水性液滴附着到显微镜（20X物镜）高速摄像机的记录图像。使用图像分析软件如微滴形态和测速软件通过巴苏25，以获得从记录的平均液滴直径。 </li><li>使用平均液滴直径来计算液滴体积，假定液滴是球形对象。 <ol><li>从这个体积和KN在微滴中的分析物的自身浓度计算对应的原子数。除以每液滴测量离子的数量由原子数，得到了检测效率。使用这种检测效率来计算未知样品的原子数。 注意:由于各个芯片之间的变化是小的22，它是没有必要重复液滴尺寸的测量为每个芯片或解决方案，如果流率保持不变。液滴大小和频率根据特定流速的列表是通过Verboket 等人 22出版。 </li></ol></li></ol>

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The authors declare that they have no competing financial interests.

虽然芯片的制造中是非常可靠的存在需要特别注意的制造过程中的一些关键点。首先，在组装过程中的清洁是非常重要的，以防止该芯片受到灰尘的污染。灰尘可阻断通道，并防止了稳定的液滴的产生。其次，它是特别重要的是，尖端被切割垂直于喷嘴通道。切口的角度强烈影响的喷射角度。如果液体被喷射在一个角度上，会引起喷射的液滴的损失。 当构建设置确保它是稳?...

液体样品通过电感耦合等离子体质谱法（ICPMS）元素分析通常进行了使用喷雾器结合雾化室作为介绍系统1。在这个样品引入系统的样品通过喷雾器喷洒以产生多分散的气溶胶。下游雾化室是用来过滤掉大滴。这种方法是用高样品消耗（&gt;0.3毫升分钟-1）2和一个不完整的检体搬送相关联。因而，变得不切实际的应用场合只微升的样品体积是可用的，如在生物，法医，毒理学和临床研究3。为了降低样品的消耗，喷雾器具有较小尺寸的喷嘴被开发3。但是，减小喷嘴尺寸增大堵塞时的未消化生物流体或浓盐溶液的样品必须被分析3的风险。 等。4。笔者注入液体到ICPMS在单分散的离散微滴，这是由压电电驱动微泵产生的形式。尽管这个系统并没有得到广泛的应用，它启动了离散液滴引入ICPMS概念的进一步发展。今天，压电电驱动分配系统，它可以在30，50，70和100微米的大小，并在100-2,000赫兹频率产生液滴，就可以买到。液滴可以被输送到ICPMS与接近100％的效率5。这些微滴分配器已申请了定量测定单个纳米颗粒5,6，以及表征个体生物细胞7。基于热喷墨技术8类似的系统，生物样品9的分析测试。虽然阿瓦伊拉布勒单个液滴引入系统是非常有效的，可用于小样品体积，并有望用于纳米颗粒和细胞的分析中，它们有若干限制。对于一个固定的喷嘴尺寸，液滴尺寸可以仅稍微被改变（除非自定义设置用于10）。液体（pH值，盐含量）的物理性质的变化可以改变墨滴的特性（尺寸，注射速度）。此外，这些设备是相当昂贵的，易发生堵塞，并且难以清洁。 另一种方法，以产生液滴已知在微流体液滴11的字段。近年来液滴微流控已获得的（生物）化学反应12-15和单细胞研究16,17兴趣。此外，这种技术应用于用于引入在电喷雾质谱18,19的样品和用于制备样品中的基质辅助激光解吸/ ionizatioñ质谱20,21。 最近，我们推出了基于微流体系统中ICPMS 22样品引入。我们引入系统的关键组成部分是辅助液体的液滴喷射（拉德）芯片。这个芯片包括完全的聚（二甲基硅氧烷）（PDMS）。在第一沟道结流动聚焦用于生成的水溶液样品溶液（ 图1）的单分散的液滴。为了这个目的和不混溶的载相全氟己烷（PFH）高挥发性（58-60℃，23沸点）时（ 图1）。这些PFH属性使稳定液滴的产生和快速去除载波相位。变化的样品液体影响本产生方法少的特性，相对于其他液滴发生器。液滴尺寸是可调节的在很宽的范围内，通过改变水相和PFH的流速。在下游secondarÝ结，更PFH被添加以增加流动速度，以至少1m秒-1。在此速度下，液体可以从在稳定和直喷射的芯片（ 图1），而不破坏液滴（ 图1插图）喷射。这双结设计让控制飞机的稳定性独立液滴产生。液滴被输送到IC​​PMS用定制的运输系统。该系统包括一个下降管和膜desolvator除去PFH。水性液滴的干燥残基被随后电离的等离子体质谱的血浆和质量检测器测量离子。芯片的前部是筒状，以确保与液滴运输系统的紧密连接。水性样品中PFH液滴的喷射是有利的，因为与喷嘴接触得以避免。这大大降低了喷嘴堵塞的危险性，用细胞悬浮液，或共同工作时这可能是一个问题ncentrated盐溶液。在拉德芯片，由PDMS制成软光刻，价格便宜（2材料成本大约为每块芯片），一次性的，容易修改。与仅需要少量的手工工作的制造组合每个实验可以用一个新的芯片来执行。因此，一个费力的清扫不需要和交叉污染最小化。 这里，拉德芯片通过软光刻和其ICPMS应用的制作进行说明。与一种水溶液和细胞悬浮液的测量实例。

<table border="0" cellpadding="0" cellspacing="0" width="919">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Name of Reagent/ Equipment</td>
			<td style="width:320px;">Company</td>
			<td style="width:147px;">Catalog Number</td>
			<td style="width:183px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Silicon wafer 100 mm</td>
			<td align="left" style="width:320px;">Si-Mat (Kaufering, Germany)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">SU-8 2002</td>
			<td align="left" style="width:320px;">Microchem Corp. (Massachusetts, U.S.A.)</td>
			<td style="width:147px;">n.a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">SU-8 2050</td>
			<td align="left" style="width:320px;">Microchem Corp. (Massachusetts, U.S.A.)</td>
			<td style="width:147px;">n.a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Acetone</td>
			<td align="left" style="width:320px;">Merk VWR (Darmstadt, Germany)</td>
			<td style="width:147px;">100014</td>
			<td></td>
		</tr>
		<tr height="42">
			<td align="left" height="42" style="height:42px;width:269px;">MR-developer 600</td>
			<td align="left" style="width:320px;">Microresist Technology GmbH (Berlin, Germany)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Isopropanol</td>
			<td align="left" style="width:320px;">Merk VWR (Darmstadt, Germany)</td>
			<td style="width:147px;">109634</td>
			<td></td>
		</tr>
		<tr height="42">
			<td align="left" height="42" style="height:42px;width:269px;">1H,1H,2H,2H-perfluorodecyltrichlorosilane</td>
			<td align="left" style="width:320px;">ABCR-Chemicals (Karlsruhe, Germany)</td>
			<td style="width:147px;">AB111155</td>
			<td></td>
		</tr>
		<tr height="42">
			<td align="left" height="42" style="height:42px;width:269px;">Sylgard 184 silicone elastomer kit (PDMS)</td>
			<td align="left" style="width:320px;">Dow Corning (Michigan, U.S.A.)</td>
			<td style="width:147px;">39100000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Perfluorohexane 99%</td>
			<td align="left" style="width:320px;">Sigma-Aldrich (Missouri, U.S.A.)</td>
			<td style="width:147px;">281042</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">FC-40</td>
			<td align="left" style="width:320px;">ABCR-Chemicals (Karlsruhe, Germany)</td>
			<td style="width:147px;">AB103511</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">Phosphate-buffered saline&#160;</td>
			<td align="left">Life Technologies (Paisley, U.K.)&#160;</td>
			<td style="width:147px;">10010-015</td>
			<td></td>
		</tr>
		<tr height="42">
			<td align="left" height="42" style="height:42px;width:269px;">Red blood cells in phosphate-buffered saline</td>
			<td align="left">Rockland Immunochemicals Inc. (Pennsylvania, U.S.A.)&#160;</td>
			<td style="width:147px;">R400-0100</td>
			<td></td>
		</tr>
		<tr height="42">
			<td align="left" height="42" style="height:42px;width:269px;">Single-element standard solutions Na, Fe</td>
			<td align="left" style="width:320px;">Inorganic Ventures (Virginia, U.S.A.)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">Multielement standard solution&#160;</td>
			<td align="left" style="width:320px;">Merck Millipore (Massachusetts, U.S.A.)</td>
			<td align="left" style="width:147px;">IV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Nitric acid</td>
			<td align="left" style="width:320px;">Sub-boiled</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">Ultrahigh-purity water</td>
			<td align="left" style="width:320px;">Merck Millipore (Massachusetts, U.S.A.)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;"></td>
			<td style="width:320px;"></td>
			<td style="width:147px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Name of Equipment</td>
			<td style="width:320px;"></td>
			<td style="width:147px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Hot plate HP 160 III BM</td>
			<td align="left" style="width:320px;">Sawatec (Sax, Switzerland)</td>
			<td style="width:147px;">n. a.</td>
			<td align="left">used for wafer preparation</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Spin modules SM 180 BM</td>
			<td align="left" style="width:320px;">Sawatec (Sax, Switzerland)</td>
			<td style="width:147px;">n. a.</td>
			<td align="left">used for wafer preparation</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">MA-6 mask aligner</td>
			<td align="left" style="width:320px;">Su&#776;ss MicroTec (Garching, Germany)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">High resolution film photomask</td>
			<td align="left" style="width:320px;">Microlitho (Essex, U.K.)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Step profiler Dektak XT advanced</td>
			<td align="left" style="width:320px;">Bruker&#160; (Massachusetts, U.S.A.)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Hot plate MR 3002</td>
			<td align="left" style="width:320px;">Heidolph (Schwabach, Germany)</td>
			<td style="width:147px;">n. a.</td>
			<td align="left">used for replica molding&#160;</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">1.5 mm biopsy puncher</td>
			<td align="left" style="width:320px;">Miltex (Pennsylvania, U.S.A.)</td>
			<td style="width:147px;">33-31AA/33-31A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Spin coater&#160; WS-400 BZ-6NPP/LITE</td>
			<td align="left" style="width:320px;">Laurell (Pennsylvania, U.S.A.)</td>
			<td style="width:147px;">n. a.</td>
			<td align="left">used for adhesive bonding</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Syringe pump neMESYS</td>
			<td align="left" style="width:320px;">Cetoni (Korbussen, Germany)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">1 mL syringe&#160;</td>
			<td align="left">Codan (Lensahn, Germany)&#160;</td>
			<td style="width:147px;">62.1002</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">5 mL syringe&#160;</td>
			<td align="left">B. Braun (Melsungen, Germany)&#160;</td>
			<td style="width:147px;">4606051V</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">PTFE tubing&#160;</td>
			<td align="left">PKM SA (Lyss, Switzerland)&#160;</td>
			<td style="width:147px;">PTFE-AWG-TFT20.N</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">Quadrupole-based ICPMS ELAN6000</td>
			<td align="left">PerkinElmer (Massachusetts, U.S.A.)&#160;</td>
			<td>n. a.&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">Membrane desolvator CETAC6000AT+</td>
			<td align="left">CETAC Technologies (Nebraska, U.S.A.)&#160;</td>
			<td style="width:147px;">n. a.</td>
			<td align="left">only the desolvator unit is used</td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;">High speed camera Miro M110</td>
			<td align="left">Vision Research (New Jersey, U.S.A.)</td>
			<td style="width:147px;">n. a.</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Data analysis program Origin pro</td>
			<td align="left" style="width:320px;">OriginLab Corp. (Massachusetts, U.S.A.)</td>
			<td align="left" style="width:147px;">version 8.6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td align="left" height="21" style="height:21px;width:269px;">Microscope</td>
			<td align="left" style="width:320px;">Olympus (Tokyo, Japan)</td>
			<td align="left" style="width:147px;">IX71</td>
			<td></td>
		</tr>
	</tbody>
</table>

a microfluidic chip for icpms sample introduction

该协议将讨论一种一次性的低成本微流体芯片作为样品引入系统，用于电感耦合等离子体质谱法（ICPMS）的制造和使用。该芯片生产的全氟（PFH）单分散水样滴。大小，并且将水的液滴的频率可以在40至60微米的范围内和从90到7000赫兹，而变化分别。液滴从芯片喷出PFH的第二流动和喷射期间保持不变。一个定制的脱溶剂系统中删除PFH和运输液滴入ICPMS。这里，具有窄强度分布非常稳定的信号，可测，显示了液滴的单分散性。我们表明，引入系统可用于定量确定在单个牛红细胞的铁。在未来，引进设备的能力可以容易地通过的额外的微流体模块一体化延长。

所提出的系统可用于测量小体积的溶液或含有细胞或纳米颗粒悬浮液。单细胞的标准溶液和表征测量的实例如下所示。更多的例子可在​​Verboket 等 22中找到。 典型的溶液中的单个液滴的信号是一个非常短的事件。它通常持续数100微秒26。同这里使用的ICPMS（停留时间10毫秒）这样的短的信号不能被暂时解决。 图7a和图7b示出的?...

Watch this Scientific Journal Video about A Microfluidic Chip for ICPMS Sample Introduction at JoVE.com

A Microfluidic Chip for ICPMS Sample Introduction

我们提出了一个离散的微滴样品引入系统，用于电感耦合等离子体质谱法（ICPMS）。它是基于一种廉价和一次性的微流体芯片，其生成高度单分散的液滴中的40-60微米的尺寸范围的频率范围从90至7000赫兹上。

微流体芯片ICPMS进样

This protocol discusses the fabrication and usage of a disposable low cost microfluidic chip as sample introduction system for inductively coupled plasma ...

a-microfluidic-chip-for-icpms-sample-introduction

Research

JoVE Journal

Bioengineering

11.1K 次观看.  ETH Zurich. 我们提出了一个离散的微滴样品引入系统，用于电感耦合等离子体质谱法（ICPMS）。它是基于一种廉价和一次性的微流体芯片，其生成高度单分散的液滴中的40-60微米的尺寸范围的频率范围从90至7000赫兹上。 

视频: A Microfluidic Chip for ICPMS Sample Introduction

Fluorescence detection methods for microfluidic droplet platforms

The development of microfluidic platforms for performing chemistry and biology has in large part been driven by a range of potential benefits that accompany system miniaturisation. Advantages include the ability to efficiently process nano- to femoto- liter volumes of sample, facile integration of functional components, an intrinsic predisposition towards large-scale multiplexing, enhanced analytical throughput, improved control and reduced instrumental footprints.1
In recent years much interest has focussed on the development of droplet-based (or segmented flow) microfluidic systems and their potential as platforms in high-throughput experimentation.2-4 Here water-in-oil emulsions are made to spontaneously form in microfluidic channels as a result of capillary instabilities between the two immiscible phases. Importantly, microdroplets of precisely defined volumes and compositions can be generated at frequencies of several kHz. Furthermore, by encapsulating reagents of interest within isolated compartments separated by a continuous immiscible phase, both sample cross-talk and dispersion (diffusion- and Taylor-based) can be eliminated, which leads to minimal cross-contamination and the ability to time analytical processes with great accuracy. Additionally, since there is no contact between the contents of the droplets and the channel walls (which are wetted by the continuous phase) absorption and loss of reagents on the channel walls is prevented.
Once droplets of this kind have been generated and processed, it is necessary to extract the required analytical information. In this respect the detection method of choice should be rapid, provide high-sensitivity and low limits of detection, be applicable to a range of molecular species, be non-destructive and be able to be integrated with microfluidic devices in a facile manner. To address this need we have developed a suite of experimental tools and protocols that enable the extraction of large amounts of photophysical information from small-volume environments, and are applicable to the analysis of a wide range of physical, chemical and biological parameters. Herein two examples of these methods are presented and applied to the detection of single cells and the mapping of mixing processes inside picoliter-volume droplets. We report the entire experimental process including microfluidic chip fabrication, the optical setup and the process of droplet generation and detection.

Droplet-based microfluidic platforms are promising candidates for high throughput experimentation since they are able to generate picoliter, self-compartmentalized vessels inexpensively at kHz rates. Through integration with fast, sensitive and high resolution fluorescence spectroscopic methods, the large amounts of information generated within these systems can be efficiently extracted, harnessed and utilized.

荧光检测方法，为微流体液滴平台

The development of microfluidic platforms for performing chemistry and biology has in large part been driven by a range of potential benefits that ...

科研

生物工程

Microfluidic Chip Fabrication and Method to Detect Influenza

Fast and effective diagnostics play an important role in controlling infectious disease by enabling effective patient management and treatment. Here, we present an integrated microfluidic thermoplastic chip with the ability to amplify influenza A virus in patient nasopharyngeal (NP) swabs and aspirates. Upon loading the patient sample, the microfluidic device sequentially carries out on-chip cell lysis, RNA purification and concentration steps within the solid phase extraction (SPE), reverse transcription (RT) and polymerase chain reaction (PCR) in RT-PCR chambers, respectively. End-point detection is performed using an off-chip Bioanalyzer (Agilent Technologies, Santa Clara, CA). For peripherals, we used a single syringe pump to drive reagent and samples, while two thin film heaters were used as the heat sources for the RT and PCR chambers. The chip is designed to be single layer and suitable for high throughput manufacturing to reduce the fabrication time and cost. The microfluidic chip provides a platform to analyze a wide variety of virus and bacteria, limited only by changes in reagent design needed to detect new pathogens of interest.

An integrated microfluidic thermoplastic chip has been developed for use as a molecular diagnostic. The chip performs nucleic acid extraction, reverse transcriptase, and PCR. Methods for fabricating and running the chip are described.

微流控芯片的制备及方法检测甲型流感

Fast  and effective diagnostics play an important role in controlling infectious  disease by enabling effective patient management and treatment. Here, we ...

A Microfluidic Chip for the Versatile Chemical Analysis of Single Cells

We present a microfluidic device that enables the quantitative determination of intracellular biomolecules in multiple single cells in parallel. For this purpose, the cells are passively trapped in the middle of a microchamber. Upon activation of the control layer, the cell is isolated from the surrounding volume in a small chamber. The surrounding volume can then be exchanged without affecting the isolated cell. However, upon short opening and closing of the chamber, the solution in the chamber can be replaced within a few hundred milliseconds. Due to the reversibility of the chambers, the cells can be exposed to different solutions sequentially in a highly controllable fashion, e.g. for incubation, washing, and finally, cell lysis. The tightly sealed microchambers enable the retention of the lysate, minimize and control the dilution after cell lysis. Since lysis and analysis occur at the same location, high sensitivity is retained because no further dilution or loss of the analytes occurs during transport. The microchamber design therefore enables the reliable and reproducible analysis of very small copy numbers of intracellular molecules (attomoles, zeptomoles) released from individual cells. Furthermore, many microchambers can be arranged in an array format, allowing the analysis of many cells at once, given that suitable optical instruments are used for monitoring. We have already used the platform for proof-of-concept studies to analyze intracellular proteins, enzymes, cofactors and second messengers in either relative or absolute quantifiable manner.

In this article we present a microfluidic chip for single cell analysis. It allows the quantification of intracellular proteins, enzymes, cofactors, and second messengers by means of fluorescent assays or immunoassays.&#160;

一个微流控芯片单细胞的多功能化学分析

We present a microfluidic device that enables the quantitative determination of intracellular biomolecules in multiple single cells in parallel. For this ...

The Multi-organ Chip - A Microfluidic Platform for Long-term Multi-tissue Coculture

The ever growing amount of new substances released onto the market and the limited predictability of current in vitro test systems has led to a high need for new solutions for substance testing. Many drugs that have been removed from the market due to drug-induced liver injury released their toxic potential only after several doses of chronic testing in humans. However, a controlled microenvironment is pivotal for long-term multiple dosing experiments,&#160;as even minor alterations in extracellular conditions may greatly influence the cell physiology. We focused within our research program on the generation of a microengineered bioreactor, which can be dynamically perfused by an on-chip pump and combines at least two culture spaces for multi-organ applications. This circulatory system mimics the in vivo conditions of primary cell cultures better and assures a steadier,&#160;more quantifiable extracellular relay of signals to the cells. 
For demonstration purposes, human liver equivalents, generated by aggregating differentiated HepaRG cells with human hepatic stellate cells in hanging drop plates, were cocultured with human skin punch biopsies for up to 28 days inside the microbioreactor. The use of cell culture inserts enables the skin to be cultured at an air-liquid interface, allowing topical substance exposure. The microbioreactor system is capable of supporting these cocultures at near physiologic fluid flow and volume-to-liquid ratios, ensuring stable and organotypic culture conditions. The possibility of long-term cultures enables the repeated exposure to substances. Furthermore, a vascularization of the microfluidic channel circuit using human dermal microvascular endothelial cells yields a physiologically more relevant vascular model.

Here, we present a protocol to coculture primary cells, tissue models and punch biopsies in a microfluidic multi-organ chip for up to 28 days. Human dermal microvascular endothelial cells, liver aggregates and skin biopsies were successfully combined in a common media circulation.

多器官芯片 - 一种微流体平台的长期多组织共培养

The ever growing amount of new substances released onto the market and the limited predictability of current in vitro test systems has led to a high need ...

Electrotaxis Studies of Lung Cancer Cells using a Multichannel Dual-electric-field Microfluidic Chip

The behavior of directional cell migration under a direct current electric-field (dcEF) is referred to as electrotaxis. The significant role of physiological dcEF in guiding cell movement during embryo development, cell differentiation, and wound healing has been demonstrated in many studies. By applying microfluidic chips to an electrotaxis assay, the investigation process is shortened and experimental errors are minimized. In recent years, microfluidic devices made of polymeric substances (e.g., polymethylmethacrylate, PMMA, or acrylic) or polydimethylsiloxane (PDMS) have been widely used in studying the responses of cells to electrical stimulation. However, unlike the numerous steps required to fabricate a PDMS device, the simple and rapid construction of the acrylic micro&#64258;uidic chip makes it suitable for both device prototyping and production. Yet none of the reported devices facilitate the efficient study of the simultaneous chemical and dcEF effects on cells. In this report, we describe our design and fabrication of an acrylic-based multichannel dual-electric-field (MDF) chip to investigate the concurrent effect of chemical and electrical stimulation on lung cancer cells. The MDF chip provides eight combinations of electrical/chemical stimulations in a single test. The chip not only greatly shortens the required experimental time but also increases accuracy in electrotaxis studies.

Many microfluidic devices have been developed for use in the study of electrotaxis. Yet, none of these chips allows the efficient study of the simultaneous chemical and electric-field (EF) effects on cells. We developed a polymethylmethacrylate-based device that offers better-controlled coexisting EF and chemical stimulation for use in electrotaxis research.

使用多通道双电场微流控芯片肺癌细胞Electrotaxis研究

The behavior of directional cell migration under a direct current electric-field (dcEF) is referred to as electrotaxis. The significant role of ...

Co-culture of Living Microbiome with Microengineered Human Intestinal Villi in a Gut-on-a-Chip Microfluidic Device

Here, we describe a protocol to perform long-term co-culture of multi-species human gut microbiome with microengineered intestinal villi in a human gut-on-a-chip microphysiological device. We recapitulate the intestinal lumen-capillary tissue interface in a microfluidic device, where physiological mechanical deformations and fluid shear flow are constantly applied to mimic peristalsis. In the lumen microchannel, human intestinal epithelial Caco-2 cells are cultured to form a &#39;germ-free&#39; villus epithelium and regenerate small intestinal villi. Pre-cultured microbial cells are inoculated into the lumen side to establish a host-microbe ecosystem. After microbial cells adhere to the apical surface of the villi, fluid flow and mechanical deformations are resumed to produce a steady-state microenvironment in which fresh culture medium is constantly supplied and unbound bacteria (as well as bacterial wastes) are continuously removed. After extended co-culture from days to weeks, multiple microcolonies are found to be randomly located between the villi, and both microbial and epithelial cells remain viable and functional for at least one week in culture. Our co-culture protocol can be adapted to provide a versatile platform for other host-microbiome ecosystems that can be found in various human organs, which may facilitate in vitro study of the role of human microbiome in orchestrating health and disease.

We describe an in vitro protocol to co-culture gut microbiome and intestinal villi for an extended period using a human gut-on-a-chip microphysiological system.

活微生物组共培养与人的微工程肠绒毛在肠道上一个芯片微流体装置

Here, we describe a protocol to perform long-term co-culture of multi-species human gut microbiome with microengineered intestinal villi in a human ...

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. 
Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Multilayer microfluidic devices often involve the fabrication of master molds with complex geometries for functionality. This article presents a complete protocol for multi-step photolithography with valves and variable height features tunable to any application. As a demonstration, we fabricate a microfluidic droplet generator capable of producing hydrogel beads.

多级可变高度的光刻多层带瓣微流体装置

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to ...

Dry Film Photoresist-based Electrochemical Microfluidic Biosensor Platform: Device Fabrication, On-chip Assay Preparation, and System Operation

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An easy-to-use and low-cost sensor platform is highly desired to measure various types of analytes (e.g., biomarkers, hormones, and drugs) quantitatively and specifically. For this reason, dry film photoresist technology - enabling cheap, facile, and high-throughput fabrication - was used to manufacture the microfluidic biosensor presented here. Depending on the bioassay used afterwards, the versatile platform is capable of detecting various types of biomolecules. For the fabrication of the device, platinum electrodes are structured on a flexible polyimide (PI) foil in the only clean-room process step. The PI foil serves as a substrate for the electrodes, which are insulated with an epoxy-based photoresist. The microfluidic channel is subsequently generated by the development and lamination of dry film photoresist (DFR) foils onto the PI wafer. By using a hydrophobic stopping barrier in the channel, the channel is separated into two specific areas: an immobilization section for the enzyme-linked assay and an electrochemical measurement cell for the amperometric signal readout.
The on-chip bioassay immobilization is performed by the adsorption of the biomolecules to the channel surface. The glucose oxidase enzyme is used as a transducer for electrochemical signal generation. In the presence of the substrate, glucose, hydrogen peroxide is produced, which is detected at the platinum working electrode. The stop-flow technique is applied to obtain signal amplification along with rapid detection. Different biomolecules can quantitatively be measured by means of the introduced microfluidic system, giving an indication of different types of diseases, or, in regard to therapeutic drug monitoring, facilitating a personalized therapy.

A microfluidic biosensor platform was designed and fabricated using low-cost dry film photoresist technology for the rapid and sensitive quantification of various analytes. This single-use system allows for the electrochemical readout of on-chip-immobilized enzyme-linked assays by means of the stop-flow technique.

干膜 Photoresist-based 电化学微流控生物传感器平台: 器件制备、片上检测制备及系统运行

In recent years, biomarker diagnostics became an indispensable tool for the diagnosis of human disease, especially for the point-of-care diagnostics. An ...

Immobilization of Live Caenorhabditis elegans Individuals Using an Ultra-thin Polydimethylsiloxane Microfluidic Chip with Water Retention

Radiation is widely used for biological applications and for ion-beam breeding, and among these methods, microbeam irradiation represents a powerful means of identifying radiosensitive sites in living organisms. This paper describes a series of on-chip immobilization methods developed for the targeted microbeam irradiation of live individuals of Caenorhabditis elegans. Notably, the treatment of the polydimethylsiloxane (PDMS) microfluidic chips that we previously developed to immobilize C. elegans individuals without the need for anesthesia is explained in detail. This chip, referred to as a worm sheet, is resilient to allow the microfluidic channels to be expanded, and the elasticity allows animals to be enveloped gently. Also, owing to the self-adsorption capacity of the PDMS, animals can be sealed in the channels by covering the surface of the worm sheet with a thin cover film, in which animals are not pushed into the channels for enclosure. By turning the cover film over, we can easily collect the animals. Furthermore, the worm sheet shows water retention and allows C. elegans individuals to be subjected to microscopic observation for long periods under live conditions. In addition, the sheet is only 300 &#181;m thick, allowing heavy ions such as carbon ions to pass through the sheet enclosing the animals, thus allowing the ion particles to be detected and the applied radiation dose to be measured accurately. Because selection of the cover films used for enclosing the animals is very important for successful long-term immobilization, we conducted the selection of the suitable cover films and showed a recommended one among some films. As an application example of the chip, we introduced imaging observation of muscular activities of animals enclosing the microfluidic channel of the worm sheet, as well as the microbeam irradiation. These examples indicate that the worm sheets have greatly expanded the possibilities for biological experiments.

Immobilization of Live Caenorhabditis elegans Individuals Using an Ultra-thin Polydimethylsiloxane Microfluidic Chip with Water Retention

A series of immobilization methods has been established to allow the targeted irradiation of live Caenorhabditis elegans individuals using a recently developed ultra-thin polydimethylsiloxane microfluidic chip with water retention. This novel on-chip immobilization is also adequate for imaging observations. The detailed treatment and application examples of the chip are explained.

超薄聚二甲基硅氧烷微氟化片在保水作用下固定化活线虫个体

Radiation is widely used for biological applications and for ion-beam breeding, and among these methods, microbeam irradiation represents a powerful means ...

Establishing Single-Cell Based Co-Cultures in a Deterministic Manner with a Microfluidic Chip

Cell co-culture assays have been widely used for studying cell-cell interactions between different cell types to better understand the biology of diseases including cancer. However, it is challenging to clarify the complex mechanism of intercellular interactions in highly heterogeneous cell populations using conventional co-culture systems because the heterogeneity of the cell subpopulation is obscured by the average values; the conventional co-culture systems can only be used to describe the population signal, but are incapable of tracking individual cells behavior. Furthermore, conventional single-cell experimental methods have low efficiency in cell manipulation because of the Poisson distribution. Microfabricated devices are an emerging technology for single-cell studies because they can accurately manipulate single cells at high-throughput and can reduce sample and reagent consumption. Here, we describe the concept and application of a microfluidic chip for multiple single-cell co-cultures. The chip can efficiently capture multiple types of single cells in a culture chamber (~46%) and has a sufficient culture space useful to study the cells&#39; behavior (e.g., migration, proliferation, etc.) under cell-cell interaction at the single-cell level. Lymphatic endothelial cells and oral squamous cell carcinoma were used to perform a single-cell co-culture experiment on the microfluidic platform for live multiple single-cell interaction studies.

This report describes a microfluidic chip-based method to set up a single cell culture experiment in which high-efficiency pairing and microscopic analysis of multiple single cells can be achieved.

使用微流体芯片以确定性方式建立基于单细胞的共培养物

Cell co-culture assays have been widely used for studying cell-cell interactions between different cell types to better understand the biology of diseases ...