Tham khảo tài liệu 'an introduction to mems engineering - nadim maluf and kirt williams part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 180 MEMS Applications in Life Sciences other DNA detection method as well as include all fluid preparation and handling functions such as pumping valving filtering mixing of reagents and rinsing. This demands the development of a complete system with many enabling technologies MEMS being only one of them. The electrophoresis part of the DNA sequencing process has been commercialized by companies such as Caliper Life Sciences Inc. of Hopkinton Massachusetts with the product now being sold as the LabChip by Agilent Technologies. Up to 12 samples containing variable-length sections of DNA are placed in the disposable LabChip which is inserted into the Agilent 2100 Bioanalyzer system for analysis. This system is about the size of a small suitcase has a separate computer for control and data acquisition and is powered by a wall outlet making the system semiportable. The entire LabChip structure is made of sheets of glass. Patterning of glasses is limited to usually photolithography and etching or laser ablation see Chapter 3 . The layers are bonded together under heat and pressure then cut apart. The use of glass in a simple process leads to low cost making a single use before disposal economical. Single-use devices have the advantages of no concern about cross contamination from previous samples greatly reduced chances of clogging and no long-term risk of material degradation with use. Many glasses and plastics are transparent to visible and UV light which is useful in optical detection schemes. Some specifications for the Agilent DNA 1000 LabChip include a DNA concentration range of ng al a sizing range of 25-1 000 base pairs a sizing accuracy of 15 and a resolution better than 10 over most of the range 19 . The sample volume is 1 al and takes 30 min to analyze. DNA Hybridization Arrays Once fragments of an unknown DNA sample have been amplified into many copies they can be read with DNA hybridization arrays. These are different sequences of preassembled .
