美国圣地亚国家实验室（Sandia National Lab）的科学家最新发明了一种手持便携式检测仪，可以在几分钟内利用少量唾液检测出牙周病及其严重程度。这是“芯片上的实验室”在实际应用中的最新进展。相关论文发表在3月27日的《美国科学院院刊》上。
这种检测仪不但将传统检测中的多个步骤整合到一个自动化仪器中，而且只需要很少量的体液，因此具有广泛的应用前景，包括诊断前列腺癌和乳腺癌，以及在疫苗开发中的动物模型的快速血清检测。该技术引起了大学和产业界的广泛兴趣，因此圣地亚国家实验室已经将该技术申请了专利。
密歇根大学的科学家们对这种新式检测仪进行了一项前期研究，将检测仪的结果与临床检测结果相比较，以确定牙周炎的生物标记的数量。
生物医学家们一直怀疑蛋白质的种类或者数量的变化可以成为检测疾病的生物标记，这项新式检测仪正是基于这种原理而产生的。圣地亚国家实验室的研究人员特别研究了唾液中的某一种酶，证明这种假说是成立的。
因为牙周炎是阶段性的，医生们需要知道牙周炎的发病阶段，才能最有效地予以治疗。科学家们监测的这种酶会随着病情的好转逐渐减少或者稳定下来。
利用可重复使用的“芯片上的实验室”，这种装置以聚丙烯酰胺凝胶为材料制成分子筛，给这种多孔凝胶加低压电流（微安培级）所产生的电泳过程会促使带电蛋白质穿过凝胶。因为这种凝胶的质地非常均匀，只允许较小的分子通过，而阻隔较大的分子，唾液中的蛋白质可以很快被分离。在这项分离过程之前，蛋白质要首先与某些被发光分子标记的抗体接触，这些抗体能够“绑定”特定生物标记。用激光清点这些合成分子——生物标记与发光抗体的结合物，就可以得到生物标记的数量，进而确定牙周炎的严重程度。
原始出处：http://www.eurekalert.org/pub_releases/2007-03/dnl-shi032907.php
部分英文原文：
Microfluidic immunoassays as rapid saliva-based clinical diagnostics
Amy E. Herr,, Anson V. Hatch, Daniel J. Throckmorton, Huu M. Tran, James S. Brennan, William V. Giannobile, and Anup K. Singh
Biosystems Research Department, Sandia National Laboratories, Livermore, CA 94550; and Michigan Center for Oral Research, School of Dentistry, University of Michigan, Ann Arbor, MI 48106
Edited by Robert H. Austin, Princeton University, Princeton, NJ, and approved January 11, 2007 (received for review August 21, 2006)
At present, point-of-care (POC) diagnostics typically provide a binary indication of health status (e.g., home pregnancy test strip). Before anticipatory use of diagnostics for assessment of complex diseases becomes widespread, development of sophisticated bioassays capable of quantitatively measuring disease biomarkers is necessary. Successful translation of new bioassays into clinical settings demands the ability to monitor both the onset and progression of disease. Here we report on a clinical POC diagnostic that enables rapid quantitation of an oral disease biomarker in human saliva by using a monolithic disposable cartridge designed to operate in a compact analytical instrument. Our microfluidic method facilitates hands-free saliva analysis by integrating sample pretreatment (filtering, enrichment, mixing) with electrophoretic immunoassays to quickly measure analyte concentrations in minimally pretreated saliva samples. Using 20 µl of saliva, we demonstrate rapid (<10 min) measurement of the collagen-cleaving enzyme matrix metalloproteinase-8 (MMP-8) in saliva from healthy and periodontally diseased subjects. In addition to physiologically measurable indicators of periodontal disease, conventional measurements of salivary MMP-8 were used to validate the microfluidic assays described in this proof-of-principle study. The microchip-based POC diagnostic demonstrated is applicable to rapid, reliable measurement of proteinaceous disease biomarkers in biological fluids.
lab-on-a-chip | point-of-care | electrophoresis | periodontal disease | micro total analysis system
英文全文链接：www.pnas.org/cgi/content/full/104/13/5268
