Nucleic Acid Sensor with Fluid Handling Components for the Detection of Salmonella enterica

摘要

An embedded controller with a keypad user interface was used to operate a nucleic acid sensor with fluid handling and real-time polymerase chain reaction (PCR) capabilities. The sensor system consisted of pumps and valves for fluid transfer, a fluorometer composed of an LED, photodiode and signal conditioning circuitry, a thermoelectric module (TEM) for heating and cooling the reaction chamber, and power switching circuitry. The amplification and dissociation results of the SYBR Green real-time PCR test can be downloaded to a PC for evaluation. Extracted Salmonella DNA in autoclaved water was automatically mixed with real-time PCR reagents and loaded into a glass reaction chamber. Alternating positive and negative control reactions were tested, andthe Salmonella sample carrying line was automatically cleaned with a combination of reagents following each reaction. Evaluation of amplification, dissociation, and agarose gel electrophoresis data indicated that carry-over contamination was not a significant problem, and therefore it was possible to reuse the same sample carrying line between runs.