Fluorescence detection in capillary arrays based on galvanometer step scanning.
A computer-controlled galvanometer scanner is adapted for scanning a focused laser beam across a 96-capillary array for laser-induced fluorescence detection. The signal at a single photomultiplier tube is temporally sorted to distinguish among the capillaries. The limit of detection for fluoresceins is 3 x 10(-11) M (S/N = 3) for 5 mW of total laser power scanned at 4 Hz. The observed cross-talk among capillaries is 0.2%. Advantages include the efficient utilization of light due to the high duty-cycle of step scan, good detection performance due to the reduction of stray light, ruggedness due to the small mass of the galvanometer mirror, low cost due to the simplicity of components, and flexibility due to the independent paths for excitation and emission.
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Ames Laboratory-USDOE and Department of Chemistry Iowa State University, USA.
Yeung
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D019075:Electrophoresis, Capillary / Q000191:economics / Q000379:methods*; D005452:Fluoresceins; D005453:Fluorescence; D007091:Image Processing, Computer-Assisted / Q000191:economics / Q000379:methods*; D007834:Lasers
D005452:Fluoresceins; C024098:6-carboxyfluorescein; C037631:2',7'-dichlorofluorescein