Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies
| Autor: | Stephen J. Hagen, Suzette A. Pabit |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Protein Folding
Time Factors Capillary action Ultraviolet Rays Mixing (process engineering) Analytical chemistry Biophysics 02 engineering and technology Sodium Iodide 01 natural sciences Nucleic Acids Jet (fluid) Millisecond Microscopy Video Dose-Response Relationship Drug Chemistry 010401 analytical chemistry Tryptophan Proteins Laminar flow equipment and supplies 021001 nanoscience & nanotechnology Fluorescence 0104 chemical sciences Microsecond Kinetics Spectrometry Fluorescence Nucleic Acid Conformation Coaxial 0210 nano-technology Research Article |
| Zdroj: | Biophysical Journal. 83(5):2872-2878 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/s0006-3495(02)75296-x |
| Popis: | The ability to mix aqueous liquids on microsecond time scales, while consuming minimal amounts of sample and maintaining UV-visible optical access to the mixing region, is highly desirable for a range of biophysical studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial jet mixer that allows the measurement of UV-excited fluorescence from nanoliter and microliter quantities of material, mixed at microsecond rates. The mixer injects a narrow cylindrical stream (radius a < 1 microm) of fluorescent sample into a larger flow of diluting buffer that moves through a capillary (100 microm i.d.) at a speed approximately 20 cm/s, under laminar flow conditions (Re approximately equal to 14). Construction from a fused silica capillary allows the laser excitation (at 266 nm) and detection (at 350 nm) of tryptophan fluorescence at reasonably low working concentrations, without interference from background fluorescence. Using this mixer we have measured sub-millisecond fluorescence quenching kinetics while consuming fluorescent sample at rates no greater than 6 nl/s. Consumption of the diluting buffer is also very modest (approximately 1-3 microl/s) in comparison with other rapid mixer designs. |
| Databáze: | OpenAIRE |
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