Fully integrated miniature device for automated gene expression DNA microarray processing.
A DNA microarray with 12,000 features was integrated with a microfluidic cartridge to automate the fluidic handling steps required to carry out a gene expression study of the human leukemia cell line (K562). The fully integrated microfluidic device consists of microfluidic pumps/mixers, fluid channels, reagent chambers, and a DNA microarray silicon chip. Microarray hybridization and subsequent fluidic handling and reactions (including a number of washing and labeling steps) were performed in this fully automated and miniature device before fluorescent image scanning of the microarray chip. Electrochemical micropumps were integrated into the cartridge to provide pumping of liquid solutions. The device was completely self-contained: no external pressure sources, fluid storage, mechanical pumps, mixers, or valves were necessary for fluid manipulation, thus eliminating possible sample contamination and simplifying device operation. Fluidic experiments were performed to study the on-chip washing efficiency and uniformity. A single-color transcriptional analysis of K562 cells with a series of calibration controls (spiked-in controls) to characterize this new platform with regard to sensitivity, specificity, and dynamic range was performed. The device detected sample RNAs with a concentration as low as 0.375 pM. Experiment also showed that the performance of the integrated microfluidic device is comparable with the conventional hybridization chambers with manual operations, indicating that the on-chip fluidic handling (washing and reaction) is highly efficient and can be automated with no loss of performance. The device provides a cost-effective solution to eliminate labor-intensive and time-consuming fluidic handling steps in genomic analysis.
Liu
Robin Hui
RH
CombiMatrix Corporation, 6500 Harbor Heights Parkway, Mukilteo, Washington 98275, USA. rliu@combimatrix.com
Nguyen
Tai
T
Schwarzkopf
Kevin
K
Fuji
H Sho
HS
Petrova
Alla
A
Siuda
Tony
T
Peyvan
Kia
K
Bizak
Michael
M
Danley
David
D
McShea
Andy
A
D010582:Bacteriophage lambda / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D020869:Gene Expression Profiling / Q000295:instrumentation*; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity