Micromachined Silicon Fluid Transfer Devices for Molecular Screening

描述（由申请人提供）：准确和快速的液体转移是几乎所有生化反应，分析或诊断测试的组成部分。虽然使用一次性聚合物移液管尖端的流体传输技术在1微升以上的体积上得到了很好的发展，但使用注射器-电磁阀、喷墨或声学分配器操作高通量筛选所需的较小体积是非常昂贵和缓慢的。利用硅微加工技术，我们的第一阶段工作已经生产出一套新的硅工具，提供了以前无法达到的多个数量级的传输量（从~50 pL到55l），价格远低于竞争技术，非常高的精度和传输速率比任何其他流体传输技术高许多倍。这种新的流体传输引脚（FTP）技术源于用于制备硅转移引脚和准直器的微加工技术中固有的极高精度，该技术可以在打印头内将引脚对准到几微米的精度。传递流体体积的准确性和动态范围的关键是在第一阶段工作中发明的硅“TwinPin”概念。摄取体积保持在两个硅销之间，这两个硅销由打印头内的微机械硅准直器保持完全平行。通过改变硅准直器来改变两平平行销轴之间的距离，可以使流体的体积在50pl到5L之间变化。此外，与任何其他类型的小体积流体分配设备不同，TwinPins可以进行湿转移（将吸入的样品浸入充满液体的目标微滴板孔中，并允许FTP的流体扩散到孔中）或干转移（以类似于微阵列打印的方式接触干燥的井底，用针尖将一小滴液体转移到井中）。借助384个元件的打印头，样品可以以比声学分配器快15倍的速度进行分配，而成本不到声学分配器的1/10。此外，使用TwinPins来打印蛋白质和DNA微阵列允许首次通过使用相同的引脚集和简单地改变准直仪来打印任何尺寸在505和>10005之间的斑点。由于大多数斑点大于~6005的蛋白质微阵列阵列是用固体引脚印刷的，在沉积每个斑点后需要洗涤和重新填充，使用TwinPins沉积大斑点将允许沉积数百个斑点，而无需重新访问源板，从而减少任何微阵列生产的时间和成本。在第二阶段的工作中，FTP技术将在UCSF的Joseph DeRisi教授和斯坦福大学功能基因组学设施主任John Coller博士的实验室中进行评估，并将他们的反馈纳入最终设计中。

DESCRIPTION (provided by applicant): The accurate and rapid transfer of fluids is an integral part of nearly every biochemical reaction, assay or diagnostic test. While fluid transfer technology using disposable polymer pipette tips is well developed for volumes above one microliter, manipulating the smaller volumes required for high throughput screening using syringe-solenoid, inkjet or acoustic dispensers is very expensive and slow. Using silicon micromachining techniques, our Phase I effort has produced a new silicon tool set that provides previously inaccessible transfer volumes over many orders of magnitude (from ~50 pL to 5 5L), a price far below competing technologies, very high accuracy and a transfer rate many times greater than any other fluid transfer technology. This new Fluid Transfer Pin (FTP) technology derives from the extremely high accuracy inherent in the micromachining technology used to prepare the silicon transfer pins and collimators which can align the pins to an accuracy of a few microns within the printhead. The key to the accuracy and dynamic range of the fluid volume transferred is the concept of the silicon "TwinPin" which was invented during the Phase I effort. The uptake volume is held between two silicon pins that are held exactly parallel to one another by the micromachined silicon collimators within the printhead. Altering the distance between the two flat parallel pin shafts by changing the silicon collimators varies the volume of fluid transferred between 50 pL and several 5L. Furthermore, unlike any other type of small volume fluid dispensing device, the TwinPins can perform both wet transfers (the imbibed sample is submersed into a liquid- filled destination microtiter plate well and the FTP's fluid allowed to diffuse into the well fluid) or dry transfers (touching a dry well bottom, in a fashion similar to microarray printing, with the pin tip to transfer a small droplet of liquid into the well). By virtue of the 384-element printhead, samples may be dispensed at a rate 15 times faster than an acoustic dispenser at <1/10th the cost. Furthermore, the use of the TwinPins to print protein and DNA microarrays allows for the first time to print any spot size between 505 and >10005 by using the same pin set and simply changing the collimator. Since most protein microarrays arrays with spots larger than ~6005 are printed with solid pins, which require washing and refilling after the deposition of each spot, use of the TwinPins for the deposition of large spots will allow hundreds of spots to be deposited without revisiting the source plate thereby decreasing the time and cost for any microarray production. In the Phase II effort the FTP technology will be evaluated in the laboratories of Prof. Joseph DeRisi at UCSF and with Dr. John Coller, Director of the Stanford Functional Genomics Facility at Stanford University and their feedback incorporated into the final designs. PUBLIC HEALTH RELEVANCE: Silicon fluid transfer pin (FTP) tools represent a technological advance that enables access to accurate and rapid extremely-low-volume transfer at a very low cost as compared to current technologies that achieve the same result. This will allow for high- throughput research to advance at all industry and academic levels without the limitations of high cost of overly technical equipment that is often difficult to setup and use. In addition to performing accurate and precise nanoliter volume transfer, the function of silicon FTPs can be expanded by applying special coatings to the pin surface from which more complex biological operations can be performed.