MICROFABRICATED DEVICES FOR GENETIC DIAGNOSTICS

This paper presents a review of microfabricated devices for genetic di agnostics. Genetic diagnostics are powerful technology drivers and exc ellent candidate applications for miniaturization technologies because the demand for inexpensive genetic information is essentially unlimit ed, and the cost and time for the diagnostic decreases with sample vol ume. Genetic information is stored in long DNA molecules in solution. This information is processed and extracted using a series of enzymati c and other chemical reactions well known in molecular biology. Proces sing of DNA molecules in the microscale hence requires the implementat ion of microfluidic devices capable of handling, mixing, thermal cycli ng, separating, and detecting nano- and picoliter liquid samples. This paper discusses some of the fundamental macroscale protocols used for genetic analyses and how these processes scale down to microscopic vo lumes. The construction and performance of microfluidic devices for DN A amplification, separation, hybridization, and detection are discusse d, showing that so far, no fundamental impediments exist for genetic d iagnostics based on microelectromechanical systems. Some of the unreso lved storage and packaging issues and future challenges for the practi cal implementation of these devices are also presented.