Parallel dual-color fluorescence cross-correlation spectroscopy using diffractive optical elements.
Dual-color cross-correlation spectroscopy allows the detection and quantification of labeled biomolecules at ultra-low concentrations, whereby the sensitivity of the assay correlates with the measurement time. We now describe a parallel multifocal dual-color spectroscopic configuration employing multiple avalanche photodiodes and hardware correlators. Cross-correlation curves are obtained from several dual-color excitation foci simultaneously. Multifocal dual-color excitation is achieved by splitting each of two laser beams (488 and 633 nm) into four sub-beams with the help of two 2x2 fan-out diffractive optical elements (DOEs), and subsequent superposition of the two sets of four foci. The fluorescence emission from double-labeled biomolecules is detected by two 2x2 fiber arrays.
Gösch
Michael
M
Karolinska Institute, Department of Medical Biochemistry and Biophysics, SE-17177 Stockholm. michael.goesch@epfl.ch
Blom
Hans
H
Anderegg
Sylvain
S
Korn
Kerstin
K
Thyberg
Per
P
Wells
Mona
M
Lasser
Theo
T
Rigler
Rudolf
R
Magnusson
Anders
A
Hård
Sverker
S
D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation* / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods