A computer numerical control (CNC) apparatus was used to perform droplet centrifugation, droplet DNA extraction, and rapid droplet thermocycling on a single superhydrophobic surface and a multi-chambered PCB heater. Droplets were manipulated using "wire-guided" method (a pipette tip was used in this study). This methodology can be easily adapted to existing commercial robotic pipetting system, while demonstrated added capabilities such as vibrational mixing, high-speed centrifuging of droplets, simple DNA extraction utilizing the hydrophobicity difference between the tip and the superhydrophobic surface, and rapid thermocycling with a moving droplet, all with wire-guided droplet manipulations on a superhydrophobic surface and a multi-chambered PCB heater (i.e., not on a 96-well plate). Serial dilutions were demonstrated for diluting sample matrix. Centrifuging was demonstrated by rotating a 10 muL droplet at 2300 round per minute, concentrating E. coli by more than 3-fold within 3min. DNA extraction was demonstrated from E. coli sample utilizing the disposable pipette tip to cleverly attract the extracted DNA from the droplet residing on a superhydrophobic surface, which took less than 10min. Following extraction, the 1500bp sequence of Peptidase D from E. coli was amplified using rapid droplet thermocycling, which took 10min for 30cycles. The total assay time was 23min, including droplet centrifugation, droplet DNA extraction and rapid droplet thermocycling. Evaporation from of 10 muL droplets was not significant during these procedures, since the longest time exposure to air and the vibrations was less than 5min (during DNA extraction). The results of these sequentially executed processes were analyzed using gel electrophoresis. Thus, this work demonstrates the adaptability of the system to replace many common laboratory tasks on a single platform (through re-programmability), in rapid succession (using droplets), and with a high level of accuracy and automation.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/610171 |
| Date | January 2012 |
| Creators | You, David, Yoon, Jeong-Yeol |
| Contributors | Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721-0038, USA |
| Publisher | BioMed Central |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © 2012 You and Yoon; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0) |
| Relation | http://www.jbioleng.org/content/6/1/15 |
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