1. Field of the Invention
The present invention relates to bio-analysis, and more particularly a bio-analysis system integrating sample preparation process, and more particularly to a multi-channel bio-analysis system integrating sample preparation process.
2. Description of Related Art
Bioanalysis, such as DNA analysis, is rapidly making the transition from a purely scientific quest for accuracy to a routine procedure with increased and proven dependability. Medical researchers, pharmacologists, and forensic investigators all use DNA analysis in the pursuit of their tasks. Yet due to the complexity of the equipment that detects and measures DNA samples and the difficulty in preparing the samples, the existing DNA analysis procedures are often time-consuming and expensive. It is therefore desirable to reduce the size, number of parts, and cost of equipment, to ease sample handling during the process, and in general, to have a simplified, low cost, high sensitivity detector.
One type of DNA analysis instrument separates DNA molecules by relying on electrophoresis. Electrophoresis techniques could be used to separate fragments of DNA for genotyping applications, including human identity testing, expression analysis, pathogen detection, mutation detection, and pharmacogenetics studies. The term electrophoresis refers to the movement of a charged molecule under the influence of an electric field. Electrophoresis can be used to separate molecules that have equivalent charge-to-mass ratios but different masses. DNA fragments are one example of such molecules.
There are a variety of commercially available instruments applying electrophoresis to analyze DNA samples. One such type is a capillary electrophoresis (CE) instrument. By applying electrophoresis in a fused silica capillary column carrying a buffer solution, the sample size requirement is significantly smaller and the speed of separation and resolution can be increased multiple times compared to the slab gel-electrophoresis method. These DNA fragments in CE are often detected by directing light through the capillary wall, at the components separating from the sample that has been tagged with a fluorescence material, and detecting the fluorescence emissions induced by the incident light. The intensities of the emission are representative of the concentration, amount and/or size of the components of the sample. In the past, Laser-induced fluorescence (LIF) detection methods had been developed for CE instruments. Fluorescence detection is often the detection method of choice in the fields of genomics and proteomics because of its outstanding sensitivity compared to other detection methods.
Heretofore, CE instruments are designed to work with samples first prepared at other devices, and then loaded onto a sample tray in the CE instruments. Some of the sample preparation procedures could be quite involved, requiring manual and/or automatic procedures. Dedicated devices and systems have been designed to handle only sample preparation, involving steps such as sample extraction, purification, amplification, stabilization, etc., to produce samples that are suitable for separation by the CE instruments. For example, DNA samples may have to be prepared by a polymerase chain reaction (PCR) process, to amplify sufficient quantities of samples from a trace amount of DNA samples. The product of the PCR process may be subject to a CE process to verify the integrity or state of the result of the PCR process. The transfer from separately prepared samples to CE separation/analysis instruments require significant manual interventions, which affect overall throughput.
It would be desirable to develop a fully integrated bio-analysis system including built-in sample preparation process capabilities, to avoid user intervention during sample preparation and separation/analysis.