Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Biomed Microdevices. 2011 Dec;13(6):973-82. doi: 10.1007/s10544-011-9567-x.
Food-borne pathogens and food safety-related outbreaks have come to the forefront over recent years. Estimates on the annual cost of sicknesses, hospitalizations, and deaths run into the billions of dollars. There is a large body of research on detection of food-borne pathogens; however, the widely accepted current systems are limited by costly reagents, lengthy time to completion, and expensive equipment. Our aim is to develop a label-free method for determining a change in DNA concentration after a PCR assay. We first used impedance spectroscopy to characterize the change in concentration of purified DNA in deionized water within a microfluidic biochip. To adequately measure the change in DNA concentration in PCR solution, it was necessary to go through a purification and precipitation step to minimize the effects of primers, PCR reagents, and excess salts. It was then shown that the purification and precipitation of the fully amplified PCR reaction showed results similar to the control tests performed with DNA in deionized water. We believe that this work has brought label free electrical biosensors for PCR amplification one step closer to reality.
近年来，食源性致病菌和食品安全相关的疫情成为了人们关注的焦点。每年因疾病、住院和死亡造成的损失估计达数十亿美元。目前已经有大量关于食源性致病菌检测的研究，但现有的被广泛认可的系统受到昂贵的试剂、冗长的检测时间和昂贵的设备的限制。我们的目标是开发一种无需标记即可检测 PCR 反应后 DNA 浓度变化的方法。我们首先使用阻抗谱来描述微流控生物芯片中去离子水中纯化 DNA 浓度的变化。为了充分测量 PCR 溶液中 DNA 浓度的变化，需要经过纯化和沉淀步骤，以最小化引物、PCR 试剂和多余盐分的影响。然后证明完全扩增的 PCR 反应的纯化和沉淀与在去离子水中进行的 DNA 对照测试结果相似。我们相信这项工作使无标记的电生物传感器用于 PCR 扩增又向前迈进了一步。
